This Spicy Honey Mustard Grilled Chicken Sandwich is loaded with juicy grilled chicken, melted mozzarella, crispy bacon, lettuce, and tomato on a toasted brioche bun.
Butterfly the chicken breasts. Place plastic wrap over them and pound to an even thickness.
Lightly coat the chicken with duck fat spray or another binder, then season with salt, pepper, and garlic powder.
Prepare a charcoal grill for direct grilling.
Combine the Dijon mustard, whole grain mustard, honey, Worcestershire sauce, cayenne, salt, and pepper. Whisk until smooth and refrigerate until needed.
Place a flat griddle over the heat and cook the bacon until crisp. Remove and set aside.
Place the chicken over direct heat and grill for 3–4 minutes per side.
After flipping the chicken, top each piece with mozzarella and allow it to melt as the chicken finishes cooking.
Toast the brioche buns on the grill.
Spread the spicy honey mustard sauce over the toasted buns.
Layer each sandwich with romaine lettuce, sliced tomato, grilled chicken, and crispy bacon.