Sprinkle chicken with seasoned salt. Let it sit and soak for 30 minutes while preparing the bacon.
Cook bacon until crisp; set aside on paper towels.
In a small bowl, mix mustard, honey, mayo, and dried onion flakes.
Sear or grill chicken until almost cooked through.
Spread mustard sauce over each piece of chicken.
Top with mushrooms, bacon, and cheese.
Cover with foil and bake at 350°F for 15–20 minutes or until cheese is melted and chicken is fully cooked.
