Preheat the oven to 400 degrees F. In a large oven-safe skillet, over medium heat, melt the butter. Add mushrooms and sprinkle with seasoned salt and pepper. Sauté until they turn brown; about 5 minutes. Place the mushrooms in a bowl and set aside. Carefully wipe out the skillet.
Using the same skillet, heat oil for a minute. Place the marinated chicken in the skillet; discarding any remaining marinade. Cook for 5 minutes on one side, or until golden-brown. Flip each piece to the other side and continue to cook for another 5 minutes or until golden-brown.
Place the cooked mushrooms over the top of each chicken breast in skillet. Top with the bacon and shredded cheese. Place the skillet in the oven. Bake until the cheese melts and internal temperature of chicken reaches 165 degrees F. (about 10 minutes or so.)
Carefully remove skillet from oven. Serve each chicken breast with a sprinkle of fresh parsley and the reserved marinade for dipping. Enjoy!