To make sauce, saute mushrooms in melted butter for 3 minutes or until tender.Stir in flour, broth and cook until mixture thickens. Stir in sour cream, pepper and Worcestershire and pepper sauces. Cook and stir 2 minutes more. To serve, place two English muffin halves on a plate.Place a poached egg on each muffin half.Spoon sauce on garnish with watercress. Serve immediately.Serves 3 to 4.