Sprinkle the chops on both sides with the garlic powder, salt and pepper. Melt butter and brown chops on both sides. Arrange chops in bottom of 9" x 13" casserole. Slice the mushrooms and scatter over the chops.
Pour the Alfredo sauce into the skillet and stir around to loosen any browned bits. Add Parmesan cheese to sauce. Pour sauce over chops. Sprinkle with thyme. Cover and bake at 300�F for 1 hour. Let rest for 10 minutes before serving.