Preheat oven to 375 degrees.
Cut bacon in half and cook, in a large ovenproof skillet (if available), over medium high heat until done. Remove bacon to paper towel lined plate and set aside. Discard all but 2 Tablespoons of bacon grease from skillet.
Add mushrooms and saute until they have released most of their liquid. As they start to release water scrape the bottom of the pan with a wooden spatula to get up the browned bits from the bacon. This adds a lot of flavor to the mushrooms. Cook until they start to turn brown. This will take about 5 to 7 minutes. Transfer to a bowl.
Season chicken with seasoning salt, pepper, and garlic powder.
Place 1 Tablespoons butter in skillet and melt . Then add chicken breasts to the skillet. Cook over medium high heat for about 4 to 5 minutes. Turn to brown and cook the other side for about 4 to 5 minutes. (If you do not have an ovenproof skillet, move chicken to a casserole or 9 X 13 baking dish for cooking).
Divide the mushrooms evenly over the chicken. Top with bacon and cheese. Bake until chicken is done or reaches 165 degrees, about 10 to 15 minutes.
Remove and garnish with parsley, if desired. Serve with reserved honey mustard sauce on the side for dipping.