1. Preheat the grill to medium-high.
2. Grill the bread slices until crisp and nicely browned, 2 to 4 minutes per side.
3. Rub each slice of bread with the cut garlic, then with the cut tomato. The idea is to apply a thin film of tomato on the bread.
4. Lightly drizzle each slice with olive oil and sprinkle with salt and pepper. Serve immediately.