Heat oven to 350°F. In a bowl, combine pepperoni, cheese, tomato, mayonnaise, and pesto. Cut each biscuit in half. Place biscuit halves into greased miniature muffin cups, pressing gently to fit cups. Spoon 1 Tbsp. of filling into each cup. Bake 20 to 25 minutes. Serve warm. Makes 40 appetizers