In a large skillet, heat the olive oil over low heat. Add the garlic and cook until softened, about 6 minutes. Reserve 1 tablespoon of garlic oil in a small bowl. Add the tomatoes to the garlic oil in the skillet and season with salt and pepper; let cool. Add the bread, mozzarella and basil and stir until moistened.
Preheat the grill to medium. Brush the steaks with the reserved 1 tablespoon garlic oil and season with salt and pepper. Transfer to the grill and cook for 7 minutes. Flip, then mound the bread mixture onto each steak. Cover and cook until the topping is golden and the cheese is melted, about 10 minutes.