- STEP 1
Fry chopped onions in the olive oil until starting to brown. Add garlic, then cumin and coriander. Cook for a couple of minutes, then add marrow. Cook for a further 5 minutes, then tip in lentils and mix thoroughly.
- STEP 2
Add chopped tomatoes, stock and the finely chopped watercress. Bring to the boil then reduce and simmer for half an hour, or until lentils are soft and mushy.
- STEP 3
Coarsely blend the soup with a hand lender. Season to taste. Allow to cool before serving.