Arrange bread slices on the rack of an unheated broiler pan. Broil 4 to 5 inches from the heat about 1 minute on each side or until toasted.
Spread a scant 1 tablespoon pesto on each slice of toasted bread; top each with a tomato slice. Crumble some of the feta cheese atop each tomato slice. Sprinkle with pepper. Watching carefully, broil 4 to 5 inches from the heat for 1 to 2 minutes or until heated through. Makes 12 to 16 slices.