Preheat a grill. Preheat the oven to 350 degrees F.
Combine butter, garlic, and 1/2 cup of the parsley, and mix well. Season with salt and pepper, to taste.
To prepare the mushrooms, remove stems, lightly coat with olive oil, and grill until tender. Place a spoonful of the butter mixture on each mushroom, and bake until butter is melted, approximately 3 minutes.
To serve, place on large platter, and sprinkle with remaining parsley.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.