Preheat the oven to 375 degrees F (190 degrees C). .
In a shallow bowl .
beat the egg with salt .
pepper and 1 teaspoon garlic powder. In a separate dish .
mix bread crumbs with 1 teaspoon of garlic powder and Parmesan cheese. Set aside. .
Mix together the melted butter and lemon juice. Pour about 2/3 of the butter mixture into the bottom of a 9x13 inch baking dish. Tilt pan to coat the bottom. Spread mushrooms in an even layer in the bottom of the dish. Dip each chicken breast into the egg mixture .
then into the bread crumb mixture. Place on top of the mushrooms. Drizzle remaining butter over the chicken .
and sprinkle with parsley. .
Bake uncovered for 45 minutes in the preheated oven .
until chicken is golden brown and juices run clear. .