Stir together tomatoes, olives, onion, vinegar, chile pepper, and garlic in a medium mixing bowl. Let stand at room temperature for 20 to 30 minutes.
Meanwhile, bias-slice bread into 1/2-inch slices. Place bread slices on a baking sheet. Bake in a 350 degree F oven about 5 minutes or until light brown. Turn bread over and bake 5 minutes more.
Evenly arrange cheese slices on toast. Drain tomato mixture. Top each cheese slice with a spoonful of tomato mixture. Return bread slices to oven; bake for 5 minutes more or until cheese melts and tomato mixture is heated through. Makes about 20 appetizers.
Wear plastic gloves while preparing peppers; thoroughly wash your hands afterward.