Melt the butter in a small pan over low heat and stir in the water. Combine all of the remaining ingredients in a large bowl and stir in the butter mixture. Remove the mushroom stems and stuff the mushrooms with the cheese mixture.
Preheat the grill to 325 degrees F.
Arrange the mushrooms, stuffing side up on the grill, and grill until cooked through, about 10 to 15 minutes. Remove the mushrooms from the grill to a serving platter and garnish with more cheese, if desired.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.