As requested !
5 oz green lentils
5 glasses of water (approximately 1 litre)
4 chopped spring onions
2 tablespoons leaf coriander (Cilantro in the US!) or parsley, chopped
1 clove garlic
1 tablespoon olive oil
1 tablespoon plain flour, mixed with 2 tablespoons cold water
1-2 tablespoons of wine vinegar
Salt and vinegar
Wash lentils in several changes of water.
Put in a pan with water to cover. Boil for 3 minutes, strain and discard the water. Place lentils in a large saucepan with a litre of cold water, spring onions, coriander, garlic and olive oil. Bring to the boil and simmer for 30 minutes until the lentils are soft, but not mushy.
Stir in the flour and water mixture, whisking all the time, and continue cooking the soup until it thickens.
Add vinegar to taste and seasonings. Don't be afraid of the vinegar, rather like adding half a glass of wine, it will just strengthen the flavour of the lentils.