Slice tomatoes in half crosswise. Using a spoon, scoop out the seeds; using a paring knife, cut out the pulp leaving shells. Coarsely chop pulp and move to a bowl. Lay hollowed out tomatoes, cut side down, on a paper towel and let drain for 5 minutes.
Mix croutons, cheese, olives, dressing, and thyme with tomato insides. Spoon mixture into cut tomatoes.
Arrange tomatoes on a baking sheet and broil for 5 minutes or until cheese melts. Serve warm.