You can stuff the mushrooms ahead, then micro-cook them just before serving.

12 large mushrooms, about 2 inches in diameter
1/2 cup finely chopped onion
2 teaspoons Gravy Master, divided
1 package (3 oz.) cream cheese, softened
1/4 cup fine dry bread crumbs
1/2 cup chopped cooked bacon or ham

Directions:

1. 1. Remove mushroom stems and chop finely. In a 1 1/2-quart casserole, place chopped stems and onion. Stir in 1 teaspoon of Gravy Master. Cover and cook on HIGH 4 minutes, stirring once.
   
2. Add cream cheese to hot mixture, mixing well. Stir in bread crumbs and bacon.
   
3. Rub mushroom caps with remaining teaspoon of Gravy Master. Arrange caps on microwave-safe platter.
   
4. Divide stuffing evenly among mushroom caps. Microwave on HIGH 3 to 4 minutes, rotating platter once during cooking time. Makes 12 mushrooms.