from Amy of ProgressivePioneer.com
1 tsp cumin seeds
1/2 coriander seeds
1 tsp ground turmeric
2 TBSP olive oil
1 chopped onion
2 chopped garlic cloves
5 cups stock (we use Better than Bouillion chicken)
10oz red lentils
1 can chopped tomatoes
Crush up the seeds in a mortar and pestle, heat them in a dry frying pan for a minute (honestly, you can skip this step too; it just intensifies the flavors). Then saute the onions and garlic in the oil and add in the spice mixture. Put in the broth and lentils and cook until the lentils are tender (about 20min). Add the tomatoes and let it cook another five minutes. Now *carefully* whiz it all up in a blender until almost smooth (a little texture is nice) and pour it back in the pot. You may need to do this in a couple batches.
If you don't have the spices in your cupboard already, that will be your big investment. Otherwise things like canned tomatoes, onions and lentils are cheap and easy to keep on hand. For garnish you can fry up some green onion slices and mix fresh parsley into some plain yogurt. I love the yogurt mixture on top!
Peter Reinhart has a wonderful recipe that comes out fluffy and chewy. But some nice whole wheat toast to dip in the soup would also be tasty and satisfying.