1/2 cup (2 ounces) shredded part-skim mozzarella cheese
How to Make It
Combine first 3 ingredients in a small bowl; stir well, and set aside. Combine tomato and next 3 ingredients in a medium bowl; stir well, and set aside.
Remove brown gills from undersides of mushrooms using a spoon; discard gills. Coat top and bottom of mushroom caps evenly with cooking spray; sprinkle with salt and pepper.
Place mushrooms, top sides up, on grill rack coated with cooking spray; grill, covered, 4 minutes. Turn mushrooms over; spoon tomato mixture evenly into caps. Top each mushroom with 1 tablespoon basil mixture and 2 tablespoons cheese. Grill, covered, 4 minutes or until mushrooms are tender and cheese melts.