01 - In a medium bowl, whisk together the maple syrup, Dijon mustard, olive oil, apple cider vinegar, garlic, thyme, salt, and black pepper until smooth and well combined.
02 - Place the chicken breasts in a large resealable bag or shallow dish. Pour the marinade over the chicken, ensuring all pieces are evenly coated. Seal or cover tightly and refrigerate for at least 1 hour, or up to 8 hours for deeper flavor penetration.
03 - Preheat your grill to medium-high heat (approximately 375–400°F). Lightly oil the grill grates to prevent sticking.
04 - Remove the chicken from the marinade, shaking off any excess. Discard the remaining marinade. Place the chicken on the hot grill and cook for 5–7 minutes per side, until the internal temperature reaches 165°F and the juices run clear.
05 - Transfer the chicken to a platter and let it rest for 5 minutes before slicing. Garnish with fresh parsley and serve alongside lemon wedges.