Saute carrots, celery, onion, and garlic in hot olive oil in a Dutch oven over medium-high heat 5 minutes or until crisp-tender. Sort and remove any debris from lentils; rinse under cold running water. Add lentils and broth to vegetable mixture; bring to a boil, reduce heat, and simmer 20 minutes, or until lentils are tender. (If you use red lentils, reduce cooking time to 5 minutes, or cook just until lentils are tender.) Season with salt and pepper. Garnish with lemon wedges and celery leaves.

The lentil, a cousin of the bean, is part of the legume family. Like beans, lentils are high in nutrients, fiber, complex carbohydrates, and folic acid.

Lentils come in several varieties. The French or European lentil, which is slightly larger, is sold with the seed coat on and has a grayish-brown exterior and a creamy-yellow interior. These are commonly sold in supermarkets. The reddish-orange Egyptian lentil is smaller, rounder, and has no seed coat; therefore, these cook in less time and add color as well as nutrition. Red lentils are often found in gourmet, Middle Eastern, or East Indian markets.

Lentils should be stored in an airtight container in a cool, dry place. Do not store in the refrigerator.