Method

For the puree

1. Place the lentils and the generous 1 ¼ cups / 325ml stock in a large saucepan and cook over a low heat until all the liquid has evaporated and the lentils are tender, about 25 minutes.
2. Remove from the heat, transfer the lentils to a blender and process, adding enough extra stock as needed, until smooth.
3. Set the puree aside until required.

For the soup

1. Heat the olive oil in a pan, add the carrots, celery, shallots, leek and garlic and sweat for 5 minutes over a low heat.
2. Add the lentils, bay leaf and thyme and the measured water and bring to the boil. Simmer for about 25 minutes, or until lentils are soft.
3. Skim any impurities from the surface of the soup, add the Savoy cabbage. Cook for a further 5 minutes or until the cabbage is cooked.
4. Check the seasoning, add the reserved puree, garnish with croutons and serve.