PREHEAT broiler. Mix oil and garlic. Brush both sides of bread slices lightly with oil mixture. Place on baking sheet. Broil 1 to 2 minutes on each side or until lightly toasted on both sides.
COVER each toast slice with 1 cheese slice; top evenly with tomatoes.
BROIL about 4 inches from heat 1 to 2 minutes or until cheese is melted. Sprinkle with oregano. Serve warm.