Heat olive oil in a large saucepan, and saute carrots, celery, and onion until just tender. Add the finely minced garlic and saute an additional minute or two.
Add tomatoes, lentils, broth, and salt, pepper, and Italian seasoning to the same pot. Bring to a boil, reduce heat and simmer for approximately or until lentils are tender. Add additional chicken broth or water if necessary, until you have achieved the desired consistency.