for the soup
2 tsp cumin seeds
pinch chilli flakes
2 tbsp olive oil
600g sweet potatoes washed, peeled and chopped up
200g split red lentils
1l hot vegetable stock (from a cube is fine)
plain yogurt and naan bread, to serve
Heat a large saucepan and dry-fry the cumin seeds and chilli flakes for 1 min, or until they start to jump around the pan and release their aromas. Scoop out about half of the seeds with a spoon and set aside. Add the oil, carrot, lentils, stock and milk to the pan and bring to the boil. Simmer for 15 mins until the lentils have swollen and softened.
Whizz the soup with a stick blender or in a food processor until smooth (or leave it chunky if you prefer). Season to taste and finish with a dollop of yogurt and a sprinkling of the reserved toasted spices. Serve with warmed naan breads.