Makes 7 cups - 6 to 8 servings

This fragrant recipe was inspired by an Egyptian soup that is sold by street vendors in Cairo. Served with fried onions and pita croutons, it’s a great main course. Red lentils don’t retain their lovely salmon color when cooked, but still, they're delicious. Take care not to overcook them; they should be tender, but not mushy.

For the soup

2 tablespoons olive oil
2 cups finely chopped onion
3 cloves garlic, minced
1 teaspoon ground cumin
1 teaspoon ground coriander
8 cups vegetable or chicken stock, divided (make stock from cubes, concentrate, or powder)
1 ¾ cups dried red lentils
2 carrots, finely chopped
½ cup coarsely chopped celery leaves
Pinch of red pepper flakes
¼ cup fresh lemon juice
Salt and freshly ground pepper to taste

For the garnishes

2 tablespoons olive oil
1 large onion, thinly sliced
2 Mediterranean or Greek pitas, halved horizontally (see Tip)
6 lemon wedges

Heat the oil in a Dutch oven over medium heat. Add the onion and garlic; cook, stirring occasionally, until the onion is translucent, about 5 minutes. Add the cumin and coriander; stir for about 30 seconds.

Stir in 6 cups of the stock, lentils, carrots, celery leaves, and red pepper flakes. Increase the heat to high and bring to a boil. Reduce the heat; cover and simmer, stirring occasionally, until the lentils are tender, about 30 minutes. Stir in the remaining 2 cups stock and the lemon juice. Season to taste.

While the soup is cooking, prepare the garnishes. Adjust the oven broiler rack to 4 to 5 inches from the heating element; preheat the broiler. Heat the oil in a large skillet over medium-low heat. Add the onion and cook, stirring occasionally, until very tender and lightly browned, about 10 minutes.

Place the pita halves on a baking sheet; toast under the broiler until crispy and light brown, about 2 minutes per side. Let cool, then break into 1-inch pieces.

Top each serving with a mound of the cooked onion and sprinkle with the pita croutons; serve a lemon wedge on the side.

Variation

Substitute brown lentils for the red lentils; increase the cooking time to about 35 minutes, or until the lentils are tender.

Advance preparation

This soup will keep for up to 5 days in a covered container in the refrigerator. When reheating, stir in vegetable stock or water to thin as desired. Store the pita croutons for up to 5 days in a tightly covered tin at room temperature.