Cook bacon in a skillet over medium heat until crisp. Transfer to paper towels. Roughly chop once cooled.
In a bowl, whisk together mayonnaise, honey, Dijon mustard, yellow mustard, lemon juice, salt, and pepper. Set aside.
Pat chicken dry. Season both sides with salt, pepper, garlic powder, onion powder, and smoked paprika.
Heat olive oil in a large oven-safe skillet over medium-high heat. Sear chicken for 3–4 minutes per side until golden.
Transfer skillet to a 375°F (190°C) oven and bake for 10–15 minutes, until chicken reaches 165°F (74°C).
While chicken bakes, melt butter in a skillet over medium heat. Add onion (if using) and cook 2 minutes. Add mushrooms and cook 6–8 minutes until browned. Stir in garlic for 30 seconds. Add Worcestershire sauce (if using), then remove from heat.
Spoon 1–2 tablespoons honey mustard over each cooked chicken breast. Top with mushrooms and bacon.
Sprinkle with Monterey Jack and cheddar. Return to oven 3–5 minutes (or broil 1–2 minutes) until cheese is melted.
Rest 5 minutes. Serve with extra honey mustard sauce.