This recipe is a Dove favorite, not only for its flavor and simplicity, but also because it came from Claudia Roden, an Egyptian Jewish (now British) food writer born in Cairo. Her Sephardic family loved this soup, whereas I encountered it in Muslim Egyptian households as a Ramadan break fast specialty. Vegans in America love this soup made with vegetarian broth (or water). It's a true Middle East peace recipe.
1 large onion, finely chopped
1 3/4 cups (350 g) split red lentils
7 1/2 cups (1 3/4 liters) meat or chicken stock or water*
Salt and pepper
1 teaspoon cumin
juice of 1/2 to 1 lemon
Extra virgin olive oil to drizzle, to taste.
In a saucepan put the onion, lentils, liquid, a little salt and pepper, and simmer 1/2 hour, or until the lentils have disintegrated. Add water if soup needs thinning. Stir in cumin and lemon juice and adjust seasoning (Leila's note - this really needs salt and lemon in generous quantity). Let people help themselves to a trickle of olive oil.
*Update, three years later. If you aren't using chicken stock, you should really, really put in a cube or two of Knorr bouillon cubes. Vegans and vegetarians will appreciate the vegetarian bouillon cubes. I made this vegan over the weekend and it's just not much fun without the Knorr cubes although you could make it so with plenty of salt and lemon.
I must get twenty referrals a day to this blog from people looking for red lentils, red lentil soup, and so forth.
Claudia lists a half dozen variations, including that of the Baghdadi Jews of India: add 1 teaspoon turmeric, and 2 dried chopped chilies or a good pinch of cayenne pepper. Read The Book of Jewish Food for more information.
In Egypt at Estoril Restaurant or the Automobile Club of Cairo, this soup was served with lime wedges and chopped fresh cilantro. Toasted pita triangles make a nice accompaniment.