Begin by trimming off any excess fat from the chicken breasts. Use a piece of plastic wrap or parchment paper to cover the chicken on a sturdy surface and gently pound the thicker end to ensure even thickness.
Transfer the chicken into a large resealable plastic bag. Pour in olive oil, Dijon mustard, honey, soy sauce, fresh lemon juice, minced garlic, onion powder, and grated ginger. Squeeze out any extra air from the bag and seal it tightly. Massage the bag to ensure the marinade coats the chicken evenly. Place it in the refrigerator for at least 4 hours or overnight, flipping the bag occasionally for better marination.
When ready to grill, preheat your outdoor grill to high heat, around 400°F (200°C), and lightly grease the grill grate to prevent sticking.
Place the marinated chicken on the grill, skin-side down. Season with a pinch of salt. Allow it to cook without moving it until it releases easily from the grill and showcases beautiful dark grill marks, which should take about 3 minutes. Lower the heat to about 350°F (175°C) or medium heat, flip the chicken, and continue cooking for an additional 5 to 7 minutes, or until the internal temperature reaches 165°F (73°C). Once cooked, remove the chicken from the grill and let it rest for 5 to 10 minutes before slicing and serving.
