In a saucepan, cover the chickpeas with water. Add the carrot, celery, onion, fennel, garlic, thyme, bay leaf and 1/4 cup of the olive oil. Bring to a simmer, cover and cook over low heat until the chickpeas are tender, about 1 hour. Let the chickpeas cool in the liquid to room temperature, then drain, reserving 3/4 cup of the cooking liquid. Discard the vegetables and herbs.