Heat the oil in a large saucepan over a medium-low heat. Tip in the onions, add a pinch of salt and fry for 10-12 mins until softened but not golden.

Add the cumin seeds, coriander and garlic, fry for a minute until fragrant, then tip in the carrots and cook for a few minutes until starting to soften. Stir in the sweet potatoes and cook for a few minutes more.

Pour in the vegetable stock, bring to a simmer (turning the heat up to medium if needed) and cook for 20-25 mins until the sweet potato and carrots are tender. Blitz using a hand blender (or transfer to a jug blender), then stir in 3-4 tbsp cream according to preference. Season to taste and serve with crusty bread, if you like.