Spiced Sweet Potato Soup

There is always a vat of soup in our kitchen; it does for lunches, snacks and sometimes even dinner, on those days when exhaustion rules out anything more arduous than lighting the gas under a pot and putting some crusty bread on a board.

Having soup always available is a useful habit to get into; it means you will never, ever have an excuse for not eating when you’re hungry, and if you have unexpected visitors nothing can be more welcoming on a cold and blustery day than a cup of thick, warming soup. If you are new to cooking, making soups is arguably the best way to fast-track your understanding of how flavours combine to become more than the sum of their parts.

This is one of those soups that started with far fewer ingredients and grew over the years as I learned which flavours would accentuate and contrast the flavours already here. Try it for yourself; use this as a starting point and experiment a bit to make this your ideal soup – that’s the way to treat all recipes.


RECIPE – serves 6-8

olive oil

3 large sweet potatoes (900g or so in total)

2 onions, chopped

4 garlic cloves, crushed

5cm knob of ginger, finely chopped

4 green birds-eye chillies, roughly chopped

1 tbsp garam masala

1 tsp ground cumin

1 tsp ground coriander

1 tsp ground turmeric

1 litre of vegetable stock

a handful of fresh coriander, stalks and leaves chopped separately

a 400 ml tin of coconut milk

the zest of a lime

1 tbsp fresh lime juice


Heat the oven to 200C/ gas 6.

Peel the sweet potatoes and chop into approximate 2cm cubes. Put into a large saucepan and drizzle 2 tbsp of olive oil over the potato cubes, then swirl and mix everything in the pan until all the cubes are lightly coated in oil. Tip onto one or two roasting trays; be careful not to crowd the cubes, you want them to roast and caramelise and they need a bit of space around them to do so. To ensure good roasting, spread the cubed potato into a single layer on each tray and ensure that they don’t touch eat other. Roast for 40-60 minutes until soft and they are just starting to caramelise and turn dark brown.

Meanwhile, using the same large saucepan you used to oil the cubed potato, heat 1 tbsp oil over a medium heat and add the onions. Gently saute them for around 10 minutes until they are soft and translucent, but not coloured. A little salt in the pan will assist the softening and delay any caramelisation.

Combine the garam masala, ground cumin, ground coriander and turmeric in a small bowl, add a little water, mix to a paste and put to one side for now.

When the onions are soft, add the garlic, ginger, and chillies. Cook for a minute or so, stirring regularly, then add the spice paste and stir thoroughly over the heat for a couple of minutes, ensuring that everything is completely coated in spice. Now add the stock and bring to a simmer; keep simmering until the sweet potatoes are ready, at which point scrape them off their roasting trays and into the simmering stock. Add the chopped coriander stalks, simmer for a further five minutes, then remove from the heat and allow to cool for a couple of minutes.

Using either a stick blender (my preferred option, just for the convenience) or a free-standing blender, blitz the soup to a smooth and even consistency – you will very likely need to add more water to loosen it. When it is completely smooth, put the soup back onto a moderate heat and add the coconut milk. Stir thoroughly and bring back to a gentle simmer, do not boil. Check and adjust the seasoning.

At this point you can either continue to finish the soup and serve it, or switch the heat off and leave it to stand for a few hours while the flavours develop even further.

When ready to serve, bring back to a simmer, add the lime zest and juice, stir well and serve scattered with chopped coriander leaves. You can make it even more impressive by adding a swirl of single cream and a scattering of cayenne pepper. Add a hunk of crusty farmhouse bread and it’s a filling, warming, feel-good soup for a winter morning, midday or evening.


Leave a Reply