lentil soup

There are so many versions of lentil soup, this is a truely delicious version, very cheap, very healthy (no fat in it at all, lentils are full of protein, iron, full of fiber, vit B1 and minerals.) and so, so easy to make.... Not really what you think of to eat in August I know, but we are having a British summer...

1 large onion, chopped finely
350g (12oz) of red slit lentils
1.75 litres (3 pints) of good quality meat, chicken or veg stock (if vegan or vegetarian)
1 tsp of ground cumin (I like to use cumin seed and freshly grind it in the pestle and mortar- get a wonderful taste and aroma)
juice of a lemon
salt and pepper

In a saucepan, put the lentils, onions, stock and salt and pepper, and simmer gently until the lentils have disintegrated. (about half an hour will do, but I like a longer time for mine) Add water if soup needs thinning. Then stir in the lemon juice and cumin, and more salt and pepper if needed.
delicious.