1. Make the sauce by mixing together the Dijon mustard, mayonnaise, and maple syrup in a bowl. Refrigerate until ready to assemble.

2. Cook bacon in a skillet over medium heat until crisp. Transfer to a paper towel-lined plate. In the same skillet, sauté onion and garlic for about 2 minutes until softened.

3. Deglaze the pan with apple juice, scraping up browned bits. Stir in cooked bacon, chopped apple, dried sage, and fresh parsley. Cook until apple begins to soften.

4. In a large bowl, combine ground chicken, panko breadcrumbs, and cooled bacon-apple mixture. Shape into 6 patties and chill for up to 30 minutes.

5. Preheat grill to medium heat. Grill patties for 6-7 minutes on one side, then flip and grill for another 6-8 minutes until internal temperature reaches 165°F. Top each patty with a slice of Monterey Jack cheese to melt in the last minute.

6. Assemble burgers by placing each grilled patty on a toasted brioche bun. Spread chilled maple-mustard sauce on the bottom bun and add desired toppings.