I swear, I cook things that aren’t soup. I’ve nearly got my vegan spag bol right, and I’ll write that up when I do. In the meantime, for this experiment, you will need:

• About a kilo of sweet potato
• About two tbs of chilli oil
• Smoked paprika
• One large onion
• Three cloves of garlic
• Two limes
• Vegetable stock

Put your oven on to 180. Peel the sweet potato and dice it into chunks. I dunno how big, make it up yourself. You’re the one roasting them. Toss them in chilli oil and about a teaspoon of smoked paprika, and bung them in to roast. You want them to take, like 20 mins or so – you’re just trying to colour them, get the edges to caramelise a little. It’s not the end of the world if they’re not all the same level of done. If you don’t have chilli oil, use regular olive oil, and then add chilli flakes to the soup at the simmering stage.

Slice the onion and the garlic, and throw them in a stock pot with some olive oil, and fry them gently, so that they’re just colouring when the sweet potato is done.

Bung the sweet potato in the pot. Cover with stock. I used about a litre and a half, but the resulting soup was quite thin, so use an amount that’ll give you the thickness of the soup you want. You could use less, if you like thicker soup. Simmer for a bit. Zest a lime, and reserve the zest. Put the juice in the soup. Simmer more. Add the chilli flakes, if you’re using them.

Blend. (I think my total simmering time was about 20 mins, just to let the flavour get to know one another and make sure the biggest chunks of the sweet potato are good and soft. Honestly, I just simmered for slightly longer than it took me to make some home-made croutons too.)

Serve finished with some of the reserved lime zest, and a squeeze of fresh lime juice in each bowl.