Follow the instructions for the Margherita topping.
Peel and finely chop the garlic clove. Finely chop enough parsley leaves to measure about 1 tablespoon. With a paper towel, gently brush any dirt from the mushrooms and thinly slice them. Put the olive oil, garlic, and parsley in a 10-inch skillet over medium-high heat. When the garlic is sizzling, add the mus