3 tablespoons olive oil, more for drizzling
1 large onion, chopped
2 garlic cloves, minced
1 tablespoon tomato paste
1 teaspoon ground cumin
¼ teaspoon sea salt, more to taste
¼ teaspoon ground black pepper
Pinch of ground chili powder or cayenne, more to taste
1 litre (quart) vegetable broth
2 cups water
1 cup red lentils
1 large carrot, peeled and diced
Juice of 1/2 lemon, more to taste
3 tablespoons chopped fresh coriander (cilantro)
In a large pot, heat 3 tablespoons oil over high heat until hot and simmering. 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.
Reheat soup if necessary, then stir in lemon juice and coriander.