Here's a recipe I've been using from http://www.habeeb.com/lebanese.recipes.index.html:
I skip the sieve for a chunkier soup and add the juice of 2 lemons when I add the onions
3 cups lentils
1/2 cup rice (optional)
1/2 cup samneh, or other shortening (I use coconut oil)
1 cup chopped onions
1 1/2 tsp. salt
Another good old fashioned soup is this one developed, of necessity, by Lebanese mountain villages when their winter diet consisted mainly of those foods which they dried in the summer and stored in earthenware jars or homespun sacks for winter eating.
Soak lentils in cold water overnight. Wash and pick over. Place in pressure cooker with water to cover them about an inch. Cook under pressure for 15 minutes. Pass the-soup through a sieve or food mill. Add water to desired consistency. Fry onions in hot fat until brown and add to soup. Simmer for 10 minutes. Add salt. Serve thick and hot with squares of crisp fried bread.
To prepare in open kettle: Wash lentils. Pick them over. Boil until soft. Pass through sieve or food mill. Add fried onions and salt. Add more water if necessary and simmer for 10 minutes.
To either method, add cooked rice if desired (one half cup before cooking). Dried pea soup may be prepared in the same way but omit rice.