Created by ladybug on May 27, 2012
Step 1: Preheat the oven to 375 degrees F. Cut off the stems of each mushroom and set aside for another use. Wipe the mushroom caps with a wet paper towel.
Step 2: Mix together the pesto and olive oil. Place the caps on a lightly oiled baking sheet and brush each cap lightly with some of the pesto oil.
Step 3: Bake the caps for about 20 minutes or until they are tender when pierced with a fork. Slice the tomato into 4 equal slices and place one on each mushroom cap. Brush with a little more of the oil, and bake an additional 10 minutes.
Step 4: Place a slice of cheese on each mushroom stack and bake until melted. Serve warm or at room temperature.