Inspired by Outback Steakhouse's original recipe.
Combine all ingredients in a bowl, whisk together until combined. Yields about 3/4 cup honey mustard.
Place 1/2 cup of the honey mustard in a ziploc bag with the chicken breasts and allow to marinate for 2 hours.
Preheat oven to 400°F.
Saute mushrooms in 2 tbsp butter until brown 8-12 minutes. Set aside.
In a large pan, sear the chicken in olive oil on medium-high heat for 3-4 minutes each side, or until golden brown. Here we're just looking for a sear and aren't cooking it through.
Transfer seared chicken into an oven safe casserole dish. Top chicken breasts with 1 slice of bacon (halved), mushrooms, and cheese. If you don't want to use the honey mustard as a dipping sauce, use a brush or spoon and top the chicken with a layer underneath the bacon.
Place the chicken in the oven and bake for 8-10 minutes or until the cheese is melted and the internal temperature of the chicken reaches 165°F.
Garnish with fresh parsley if desired.