1 tablespoon olive oil
1 onion, finely chopped
3 cloves garlic, minced
1 teaspoon ground cumin
1 teaspoon ground coriander
1/2 teaspoon curry powder
2 cups red lentils, rinsed and picked through
3 to 4 cups vegetable stock
1 (14 1/2 ounce) can diced tomatoes
5 ounces baby spinach
Salt and pepper, to taste
1 tablespoon lemon juice
Heat oil in a large soup pot over medium heat. Add onions and cook until soft, about 7 minutes. Stir in garlic, cumin, coriander, curry and lentils. Cook until fragrant, 2 to 3 minutes. Pour in vegetable stock and tomatoes, to cover. Bring to a boil. Reduce to a simmer and cook until lentils are tender, about 20 minutes.
For a creamier soup, whisk or mash half of the soup.
Stir in spinach, salt, pepper and lemon juice. Cook until the spinach just wilts, 2 to 3 minutes.