Step 1: In a medium bowl, gently combine the ground chicken with salt and pepper. Be careful not to overmix.
Step 2: Form the mixture into four equal-sized patties, approximately 1-inch thick. Create a slight indentation in the center of each patty to prevent bulging during cooking.
Step 3: In a small bowl, whisk together the Dijon mustard, maple syrup, apple cider vinegar, and Worcestershire sauce to create the glaze.
Step 4: Preheat your grill or a large skillet to medium-high heat. Lightly oil the grates or pan.
Step 5: Place the chicken patties on the hot grill or skillet. Cook for 6-8 minutes per side, or until the internal temperature reaches 1650F (740C).
Step 6: During the last 5 minutes of cooking, brush the patties generously with the maple mustard glaze, flipping once to coat both sides and allow the glaze to caramelize.
Step 7: While the burgers finish cooking, lightly toast the burger buns on the grill or in a separate pan.
Step 8: Assemble the burgers: Place a lettuce leaf on the bottom bun, followed by a glazed chicken patty, tomato slice, red onion slices, and pickle slices. Top with the other half of the bun and serve immediately.