Preparation In a large pot, heat 3 tablespoons oil over high heat until hot and shimmering. Add onion and garlic, and sauté until golden, about 4 minutes. Stir in tomato paste, cumin, salt, black pepper and chili powder or cayenne, and sauté for 2 minutes longer. Add broth, 2 cups water, lentils and carrot. Bring to a simmer, then partially cover pot and turn heat to medium-low. Simmer until lentils are soft, about 30 minutes. Taste and add salt if necessary. Using an immersion or regular blender or a food processor, purée half the soup then add it back to pot. Soup should be somewhat chunky.