6 tablespoons olive oil, divided
1 large onion, chopped
2 garlic cloves, minced
1 teaspoon ground cumin
¼ teaspoon salt, more to taste
¼ teaspoon ground black pepper
Pinch of ground cayenne powder
4 cups chicken or vegetable broth
2 cups water
1 cup red lentils
Juice of ½ lemon, or to taste
4 tablespoons chopped fresh cilantro.
In a large pot, heat 3 tablespoons oil over high heat until hot. Add onion and garlic, and sauté until golden. Stir in cumin, salt, pepper and cayenne and sauté for 2 minutes longer. Add broth, water and lentils; bring to a simmer. Partially cover pot, turn heat to medium-low and cook until lentils are soft, about 20 minutes. Add the lemon juice. Taste and add salt if necessary.
Transfer half the soup to a large bowl and purée with an immersion blender. Alternately, purée soup in a blender or food processor. Add puréed soup back to the pot.
Purée the cilantro with the remaining 3 tablespoons olive oil and a pinch of salt. Stir pesto into the soup. Adjust the seasonings.
Adapted from "Mark Bittman's Kitchen Express" (Simon & Schuster, 2009)