In a large saucepan, heat oil at medium heat. Add veggies and garlic, cook, stirring often, 5 to 8 minutes or until veggies are lightly golden.
Add broth, lentil and tomatoes with their juice. Add salt and pepper. Bring to boil, reduce heat to medium and let simmer for about 15 minutes or until veggies are tender (add more broth if the soup becomes to thick).