Whisk together honey, Dijon mustard, mayonnaise, and lemon juice in a small bowl until smooth. Reserve ½ cup of sauce and set aside. Pour remaining honey mustard sauce into a gallon-sized Zip lock bag and add chicken. Marinade for 1 hour, up to 24 hours.
Preheat oven to 400 degrees and line a baking sheet with parchment paper.
In a heavy-bottomed skillet, heat 2 tablespoons of olive oil over medium-high heat until it shimmers.
Remove chicken from the marinade with tongs and place into hot skillet. Season each side with salt and pepper and cook until golden brown but not cooked through, working in batches as not to over-crowd the pan.
Place browned chicken on prepared baking sheet.
In the same skillet, add butter and melt over medium heat. Stir in mushrooms and a pinch of salt, and cook until tender and starting to brown. Remove from heat.
Divide and spoon mushrooms over the chicken breasts, followed by 2 slices of bacon, and the Monterrey jack cheese.
Bake for 10-15 minutes or until the thickest part of the chicken reaches 165 degrees.
Top with fresh parsley and serve with reserved honey mustard sauce for dipping.