Add ½ cup low-sodium soy sauce, ⅓ cup rice vinegar, 6 cloves garlic, 2-3 bay leaves, ½ teaspoon whole peppercorns, 2 teaspoons brown sugar, 2 tablespoons olive oil, ¼ teaspoon red pepper flakes, and 1-2 green onions to medium mixing bowl. Whisk well until ingredients are fully incorporated. Set aside.
Place equally-sized chicken breasts in sealable food-safe bag. Pour marinade into bag, covering chicken completely, then seal bag while removing as much air as possible.
Gently massage chicken through bag until each chicken breast is completely covered in marinade. Place sealed bag in refrigerator and marinate chicken at least 1 hour, but no more than 12 hours.
Toward end of marinating team, preheat grill to medium-high, approximately 375° to 400° Fahrenheit. Once grill is preheated, use tongs to remove chicken breasts from marinade, shaking any excess marinade back into bag. Place chicken breasts directly on grill over indirect heat.
Grill chicken, uncovered, 7 to 10 minutes or until chicken is golden-brown on bottom. Carefully flip chicken breasts over and grill 7 to 10 minutes more, or until internal temperature of chicken reaches 160° Fahrenheit when checked with internal meat thermometer.
Once temperature is reached, carefully remove chicken from grill and transfer to large plate. Set chicken aside to rest 5 minutes, then slice chicken and serve warm with desired sides.
Recipe Notes
Cook times will vary depending on size and thickness of chicken breasts.
Make it Gluten Free: Use gluten-free soy sauce, or replace the soy sauce with lite tamari or coconut aminos.
Make it Keto: Replace the brown sugar with Brown Swerve.