PREHEAT oven to broil and position oven rack 6 inches from broiling element.
COMBINE goat cheese, Parmesan cheese, Gruyère cheese and pepper in medium bowl; stir well.
SLICE bread into 30 (1/4-inch) slices. Arrange on baking sheet and lightly brush tops with olive oil. Broil for about 1 minute or until light golden.
SPREAD each bread slice with ½ to 1 teaspoon of the cheese mixture and return to oven. Broil until cheese begins to melt and brown.
TOP each slice with two tomato pieces. Serve immediately.