Cooking your sweet potato harvest: six recipes, from roast wedges to Gujarati saak

A sweet potato harvest arrives all at once in autumn. Cured tubers keep for months in a cool, dark cupboard, so there is no rush, and the three varieties each suit different dishes: Beauregard for roasting and soup, Eclipse for mash, Northern Star for crisp wedges and chips. The young leaves and shoot tips of any of them make a quick garlic stir-fry, so a sweet potato bed feeds you long before the tubers are ready.

These six recipes are simple, and all of them work with shop-bought sweet potatoes while you wait for your own. The last two travel further afield: a Gujarati fasting-day dish that cooks sweet potato and potato in the one pan, and a Japanese snack that was sold hot to students outside Tokyo campuses a century ago.

A note on curing first

Freshly dug sweet potatoes taste starchy and bland. A week or two of curing somewhere warm, humid and airy converts some of that starch to sugar and heals the skin, and the difference in flavour is noticeable. If you have just lifted your crop, cure it before you cook it. Our growing guide covers curing and storage.

Smoky roast sweet potato wedges (Beauregard or Northern Star)

Beauregard gives soft, caramelised wedges. Northern Star gives drier, fluffier ones with a crisper edge. Both are good, and the recipe is the same.

Serves 4 as a side.

• 800 g sweet potatoes, scrubbed, skin on
• 2 tablespoons olive oil
• 1 teaspoon smoked paprika
• 1 teaspoon ground cumin
• Half a teaspoon of salt
• Plain yoghurt and a lime, to serve

1. Heat the oven to 210°C and line a large tray with baking paper.
2. Cut the sweet potatoes lengthways into wedges about 2 cm thick at the widest point. Keep them even so they cook at the same rate.
3. Toss the wedges with the oil, paprika, cumin and salt until every piece is coated.
4. Spread them in a single layer with a little space between each wedge. Crowding steams them instead of roasting them.
5. Roast for 30 to 35 minutes, turning once halfway, until the edges are dark and the middles are soft.
6. Serve hot with a spoon of yoghurt and a squeeze of lime.

The skins are edible and hold the wedges together, so leave them on. If the tray looks wet after turning, give the wedges an extra five minutes with the oven door cracked open.

Purple sweet potato mash with coconut and lime (Eclipse)

Eclipse is the mash variety. The flesh is dense and drier than the orange types, with a mild rather than sugary sweetness, and steamed rather than boiled it holds its violet colour instead of leaching it into the pot.

Serves 4.

• 700 g Eclipse sweet potatoes, peeled and cut into 3 cm chunks
• 100 ml coconut milk
• 1 tablespoon butter or olive oil
• Finely grated zest and juice of half a lime
• Salt, to taste
• A few coriander leaves, to serve

1. Steam the sweet potato chunks over simmering water for 15 to 20 minutes, until a knife slides in with no resistance.
2. Tip them into a warm bowl and mash with a fork or potato masher. Purple sweet potato mashes drier than orange, so do not expect it to go silky.
3. Warm the coconut milk with the butter, then beat it into the mash a little at a time until it is as soft as you like.
4. Stir through the lime zest and juice and season with salt.
5. Serve with a scatter of coriander.

The colour varies from tuber to tuber, from marbled lavender to deep violet, and a squeeze of lime shifts the colour warmer, towards red violet. That variation is normal for Eclipse.

Garlic sweet potato leaf stir-fry (any variety)

The young leaves and shoot tips of a sweet potato vine are a proper vegetable, eaten across Asia, Africa and the Pacific, and a light picking every week or two costs the crop very little, though stripping the vines hard will cut the tuber yield. They taste a little like spinach with a hint of green bean, and they cook in minutes.

Serves 2 as a side.

• Two large handfuls of young sweet potato leaves and tips, about 200 g
• 1 tablespoon neutral oil
• 2 cloves garlic, sliced
• 2 tablespoons water
• 2 teaspoons soy sauce or fish sauce
• A pinch of chilli flakes, if you like

1. Pick the tender tips and the youngest leaves, discarding any thick, woody stem. Wash them well and shake dry.
2. Heat the oil in a wok or wide pan over high heat until it shimmers. Add the garlic and stir for 20 seconds, until fragrant but not brown.
3. Add the leaves all at once. They will look like far too many. Toss for a minute until they start to collapse.
4. Add the water and the soy or fish sauce, toss for another minute or two until the stems are tender and the pan is nearly dry.
5. Finish with the chilli flakes and serve straight away.

Cook the leaves rather than eating them raw. Raw leaves hold soluble oxalates that leave a chalky feel in the mouth, and a minute or two in a hot pan deals with that. Pick only from vines that have not been sprayed.

Sweet potato and ginger soup (Beauregard for colour)

This is the recipe for the odd-shaped tubers and the ends of the crate. Beauregard gives the richest colour, but any variety works, and a mix is fine.

Serves 4.

• 1 tablespoon olive oil
• 1 onion, chopped
• 1 thumb of fresh ginger, peeled and grated
• 1 teaspoon ground coriander
• 800 g sweet potato, peeled and chopped
• 1 litre vegetable or chicken stock
• 200 ml coconut milk
• Salt and lime juice, to finish

1. Warm the oil in a large pot over medium heat and soften the onion for five minutes without colouring it.
2. Add the ginger and ground coriander and stir for a minute.
3. Add the sweet potato and stock, bring to the boil, then simmer for 20 minutes until the sweet potato is completely soft.
4. Blend until smooth, stir in the coconut milk and warm through.
5. Season with salt and a good squeeze of lime, and serve with toasted seeds or a swirl of yoghurt.

The soup freezes well, so a crate of sweet potatoes can become a freezer of dinners in one afternoon.

Sakkariya batata nu saak: the Gujarati way with two tubers

Sakkariya is sweet potato, batata is potato, and a saak is the dry vegetable dish that sits beside dal and rotli on a Gujarati thali. Cooking the two tubers in the same pan is not a fusion idea invented for a blog. It is how the dish is often made on a fasting day, when both tubers are permitted and grain is not.

That fasting connection is also why the salt matters. On those days many households cook with sendha namak, an unrefined rock salt, in place of ordinary table salt. Himalayan pink salt is that same rock salt, so if you have a grinder of it in the cupboard you already have the right thing. It tastes rounder and less sharp than table salt, which suits the sweetness of the sakkariya.

There is no onion and no garlic, which is part of the same tradition, and the dish does not want for them. The flavour comes from cumin seeds bloomed in hot ghee, green chilli, ginger and a generous amount of fresh coriander.

Serves 4 as a side, or 2 with rotli.

• 400 g sweet potato, Beauregard or Northern Star, peeled and cut into 2 cm cubes
• 400 g waxy potato, peeled and cut into 2 cm cubes
• 2 tablespoons ghee, or a neutral oil
• 1 teaspoon cumin seeds
• 1 green chilli, slit lengthways, or chopped if you want more heat
• 2 teaspoons finely grated fresh ginger
• Quarter of a teaspoon of ground turmeric
• 1 teaspoon Himalayan pink salt, or to taste
• 1 teaspoon caster sugar
• Juice of half a lemon
• A large handful of coriander leaves and stems, chopped
• 2 tablespoons roasted peanuts, coarsely crushed, to serve

1. Keep the two tubers in separate bowls as you cut them. Sweet potato softens faster than potato, so they do not go into the pan at the same moment.
2. Heat the ghee in a heavy pan over medium heat. Add the cumin seeds and wait for them to darken a shade and smell toasted, which takes about twenty seconds. Do not let them blacken.
3. Add the chilli and ginger and stir for half a minute.
4. Add the potato, the turmeric and the salt. Stir to coat, then cover and cook on low for eight minutes, stirring once.
5. Add the sweet potato and the sugar. Stir gently, cover again, and cook for a further eight to ten minutes, until both tubers are tender but still holding their shape. Stir as little as you can from this point, or the sweet potato will collapse into the potato.
6. Take the pan off the heat. Add the lemon juice and most of the coriander and fold through once.
7. Serve warm, scattered with the crushed peanuts and the last of the coriander.

The sugar is not a mistake. A little sweetness in a savoury saak is ordinary in Gujarati cooking, and here it lifts the ginger and the lemon rather than making the dish taste sweet. Leave it out if you would rather.

If the cubes catch on the base of the pan, add a tablespoon of water and put the lid straight back on. The steam lifts them off without any stirring.

Daigaku imo: the Japanese snack named after a university

This is the one to make if you want something genuinely new on the table. Daigaku imo translates as university potato, and the name is literal. A century ago, stalls in the university district of Tokyo sold these hot in paper bags to students, and the name stuck to the dish.

Chunks of sweet potato are fried until the edges crisp, then turned through a dark caramel of sugar, honey and soy and showered with black sesame. The result lands sweet, salty and just short of sticky, somewhere between a side dish and a dessert, and it is eaten warm with fingers or a pick.

Traditionally the chunks are deep fried, which means a saucepan of oil and the bother of dealing with it afterwards. The method below shallow fries in about a centimetre instead, which gets you most of the way there. There is an oven version at the end if you would rather not fry at all.

One detail decides the texture. Cut the sweet potato rangiri style, which means rolling the tuber a quarter turn between each diagonal cut so that every piece has faces at different angles. More surface means more crisp edges, and more caramel clinging to them.

Serves 4 as a snack.

• 700 g sweet potato, Beauregard or Northern Star, skin on, scrubbed
• A neutral oil for shallow frying, about 250 ml
• 3 tablespoons caster sugar
• 1 tablespoon honey
• 1 tablespoon soy sauce
• 1 tablespoon water
• 1 teaspoon rice vinegar
• 2 teaspoons black sesame seeds

1. Cut the sweet potato rangiri style into pieces about 3 cm across: make a diagonal cut, roll the tuber a quarter turn, cut again, and keep going to the end.
2. Sit the pieces in a bowl of cold water for ten minutes, then drain and dry them thoroughly in a tea towel. The soak takes off surface starch and the drying stops the oil spitting.
3. Heat the oil in a wide pan to about 160°C, or until a test piece sizzles steadily without browning straight away. Fry in two batches for six to eight minutes each, turning now and then, until the pieces are tender through and pale gold.
4. Lift them onto paper towel. Raise the heat a little and return them for a final minute to crisp the outsides, then drain again.
5. Pour the oil out of the pan but do not wash it. Add the sugar, honey, soy, water and vinegar and bring to a simmer over medium heat. Let it bubble for two to three minutes, until it thickens and just begins to darken. Leave it alone once it is simmering rather than stirring.
6. Take the pan off the heat, tip in the sweet potato, and turn it through the caramel until every piece is glossy.
7. Scatter with black sesame and serve warm, spread out on the plate rather than heaped, or the pieces weld to each other as they cool.

The vinegar is there to keep the syrup from crystallising, so do not leave it out. If the caramel sets hard before the sweet potato goes in, add a spoon of water and warm it through again.

To roast instead of fry, toss the pieces in two tablespoons of oil and roast at 220°C for about 30 minutes, turning once, then make the caramel separately and coat them in it. The edges come out less crisp, but the dish still works.

Beauregard gives the sweeter, softer result. Northern Star holds its shape best and crisps hardest, which is what you want here.

Storing the harvest so it lasts

Cured sweet potatoes keep for several months in a cool, dark cupboard with some airflow. Very dry air makes them shrivel, so a pantry suits them better than a heated room, and they do not belong in the fridge, where the cold turns the centres hard and the flavour flat. Check the crate every few weeks and cook anything that has gone soft first.

If you would like to grow your own, our foundation seed tubers are available in spring and our variety comparison explains which one suits your kitchen. If you are starting from a planting tuber, the slips guide and the zone by zone calendar will get the crop in the ground.

Due to quarantine restrictions and our shipping policy, we cannot send sweet potato tubers to Western Australia or Tasmania.

Get the tubers

First generation foundation seed tubers from an Australian specialist grower, supplied clean for sprouting your own slips. Packs of 2, 4 or 10 tubers, all in our sweet potato tuber collection.

More sweet potato guides

• How to grow sweet potatoes in Australia, from tuber to harvest
• When to plant sweet potatoes, zone by zone
• How to sprout sweet potato slips from a tuber
• Beauregard, Eclipse or Northern Star: which one to grow
• Sweet potato tubers: Beauregard, Eclipse and Northern Star

Frequently asked questions

Can you eat sweet potato leaves?

Yes. The young leaves and shoot tips are a traditional cooked green across Asia, Africa and the Pacific. Wash them well and cook them briefly rather than eating them raw, and only pick from plants that have not been sprayed.

Do I need to peel sweet potatoes?

Not for roasting. The skin is edible, holds wedges together and crisps up nicely. Peel for mash and soup, where a smooth texture matters.

Why does my purple sweet potato lose its colour when boiled?

The purple pigments dissolve into the cooking water. Steaming, roasting or microwaving keeps far more colour in the flesh than boiling.

Which sweet potato is best for chips and wedges?

Northern Star gives the driest, crispest result. Beauregard gives softer, sweeter wedges with caramelised edges. Northern Star is the better choice for chips.

Is Himalayan pink salt the same as sendha namak?

Effectively yes. Sendha namak is unrefined rock salt, and Himalayan pink salt is rock salt mined from the same part of the world, which is why it stands in for it in the saak. Both taste rounder and less sharp than refined table salt.

Do I have to deep fry the daigaku imo?

No. The method here shallow fries in about a centimetre of oil, and there is an oven version at the end of the recipe as well. Deep frying gives the crispest edges, but the caramel does most of the work, and the roasted version is still very good.

How long do sweet potatoes keep?

Cured tubers usually keep for several months in a cool, dark, airy cupboard. Do not refrigerate raw sweet potatoes.

Can I freeze sweet potato?

Cooked, yes. Mash, soup and roasted chunks all freeze well. Raw sweet potato does not freeze well and goes watery when thawed.