INSTRUCTIONS
1. Preheat oven to 375°F. Place mushroom caps in a greased 15x10x1-in. baking pan. Bake 10 minutes. Meanwhile, place mayonnaise, Asiago cheese, basil and pepper in a food processor; process until blended.
2. Drain juices from mushrooms. Fill each with 1 rounded teaspoon mayonnaise mixture; top each with a tomato half.
3. Bake until lightly browned, 8-10 minutes. If desired, top with Parmesan cheese.