Sweet potato, cumin and coriander soup

Heat the oil in a large saucepan and fry the onions, carrots and potatoes until beginning to soften - about 10 minutes.

Add the cumin and curry powder and stir until the vegetables are well coated.

Stir in the vegetable stock cube, sugar and coconut milk. Simmer for 20 minutes, or until the vegetables are soft.

Blend the soup until smooth, using a stick blender. You can also use a liquidizer for this. Stir in the coriander.

For the sweet potato crisps, peel the potato and pare into ribbons using a vegetable peeler. Heat the oil until very hot and fry the ribbons in batches, until golden. Drain on kitchen paper and serve with the soup.