Indian Red Lentil Soup

I attempted this soup last night, inspired mostly by the fact that the recipe looked easy and nutritious. I was hoping it would taste good too. I'm trying to diet (by eating in a South Beach way) until Thanksgiving...at which time, all bets are off!

Anyway, it was delicious! It's from the Williams-Sonoma book Soup for Supper. I'll definitely be adding this recipe to my repertoire of easy-to-make, low-cal meals:

Indian Red Lentil Soup
SERVES 6
1 1/2 cups red lentils
3 tablespoons unsalted butter
1 large yellow onion, chopped
2 tablespoons ground coriander
2 teaspoons ground cumin
2 teaspoons peeled and grated fresh ginger
1/2 teaspoon ground turmeric
1 pinch cayenne pepper
6 cups water or vegetable stock or chicken stock
1 1/2 cups peeled seeded and diced tomatoes (fresh or canned)
2 tablespoons lemon juice (to taste)
salt & fresh ground pepper
3 tablespoons chopped fresh mint or fresh cilantro

Pick over the red lentils and discard any misshapen lentils or stones. Rinse lentils and drain. In a saucepan over medium heat, melt the butter. Add the onion and saute, stirring occasionally, until tender and translucent (8 to 10 minutes). Add the coriander, cumin, ginger, turmeric, and cayenne and stir to mix well. Reduce the heat to low and cook, stirring occasionally, to release the flavors of the spices (2 to 3 minutes).

Add the lentils and then gradually add the water or stock, stirring constantly. Bring to a boil over high heat, reduce the heat to low, cover partially, and simmer until the lentils are very soft (30 to 40 minutes). Remove from the heat and let cool slightly.

Working in batches, puree the soup in a blender or food processor. Return the soup to a clean saucepan and place over medium heat. Stir in the tomatoes and lemon juice and cook until heated through. Season with salt and black pepper.