Gather the ingredients.

Combine lentils, carrots, onion, garlic, bay leaf, and thyme in a saucepan. Add enough water to cover by 1 inch; bring to a boil, reduce heat and simmer uncovered for 15 to 20 minutes or until lentils are tender but not mushy.

Drain lentils and vegetables and remove bay leaf. Add olive oil, lemon juice, celery, parsley, salt and pepper. Toss gently to mix and serve at room temperature.