In a small bowl, stir together pepperoni, cheese, and chili sauce; blend well. (At this point you may cover and refrigerate for up to a week.)
Arrange 12 toast rounds in a circle on a flat 10 or 12 inch plate.
Spoon about 1 teaspoon pepperoni mixture on each toast round.
Microwave, uncovered, on HIGH (100%) for 1 minute (rotating plate 1/4 turn after 30 seconds) or until cheese is melted.
Repeat with remaining toast rounds.