Preheat the oven to 350 degrees. Place the pie crust in a 9-inch pie pan; sprinkle with the Swiss and Parmesan cheeses. In a sauté pan, melt the butter over medium heat. Sauté the mushrooms until softened, about 5 minutes. Pour the mushrooms in the pie shell. In a medium bowl, beat together the eggs, cream, white pepper, salt and Worcestershire, and pour the mixture over the cheese and mushrooms. Bake until golden and set, about 35 minutes. Cool slightly before cutting and serve warm. Serves 8.