Vinegar is added to lentils to make them more easily digestible; I find cider vinegar more suitable here because it is sweeter.
Serves 6–8
450 g (1 lb) green lentils, such as Puy or Castelluccio
5 tbsp olive oil
1 onion, finely chopped
1.5–1.75 litres (2 1/2–3 pints) meat or vegetable stock
a dozen fresh sage leaves, chopped
2 tbsp cider vinegar
sea salt and freshly ground black pepper
Check that the lentils do not contain any stones or grit and then rinse and drain them.
Put the oil and the onion in an earthenware pot or a heavy-bottomed saucepan and sauté on medium heat until the onion is soft.
Add the sage to the onion, stir and then add the lentils. Stir until the lentils are well coated with oil and then add enough boiling stock to cover the lentils. Bring the liquid to the boil, turn down the heat, cover the pan and simmer for about 30–40 minutes. The cooking time varies depending on the variety of the lentils and also on how long they have been in store. During the cooking add a little hot water or stock if necessary, so that the lentils will not cook dry. Halfway through the cooking, stir in the vinegar and continue cooking until the lentils are tender. By the time they are cooked they should have absorbed nearly all the liquid.
Add salt and pepper to taste, mix well and serve at once.
preparation
Lentils are better done a day in advance. They can also be frozen.