By Melissa Clark, updated June 24, 2024, New York Times Cooking
In a large pot, heat 3 tablespoons of olive oil over high heat until hot and shimmering. Add the onion and garlic, sautéing until golden, about 4 minutes.
Stir in the tomato paste, cumin, 1 teaspoon each of salt and black pepper, and the chili powder. Cook for another 2 minutes.
Add the broth, 2 cups of water, lentils, and carrot. Bring to a boil, then partially cover the pot and reduce heat to medium-low. Simmer until the lentils are tender, about 30 minutes. Taste and add more salt if needed.
Using an immersion blender (or a regular blender or food processor), puree half of the soup, then return it to the pot. The soup should have a slightly thick consistency.
Reheat the soup if needed, then stir in the lemon juice and cilantro. Serve drizzled with good olive oil and lightly sprinkled with chili powder, if desired.