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. Add the oil and
onion, and cook for 5 mins. Stir in the
lentils, stock and tomatoes, then bring
to the boil. Simmer for 15 mins until the
lentils have softened.
Whizz the soup with a stick blender
or in a food processor until it is a rough
purée, pour back into the pan and add
the chickpeas. Heat gently, season well
and stir in the coriander. Finish with
a dollop of yogurt and coriander leaves.