Marinate the Chicken: In a large mixing bowl, whisk together the soy sauce (¾ cup), ketchup (¾ cup), brown sugar (½ cup), minced ginger (1 tablespoon), minced garlic (8 cloves), and avocado oil (⅓ cup) until fully combined. Place the chicken thighs (3 lbs) in a large resealable bag or a shallow dish. Pour the marinade over the chicken, ensuring each piece is well-coated. Cover and refrigerate for at least 2 hours or up to overnight for the best flavor.
Prepare the Sauce: Once the chicken has marinated, remove it from the marinade and set it aside. Pour the leftover marinade into a small saucepan and bring it to a gentle simmer over medium heat. Let it cook for 5-7 minutes, stirring occasionally, until slightly thickened. This will be used for basting the chicken and as a serving sauce.
Grill Method: Preheat the grill to medium-high heat (about 375-400°F). Lightly oil the grill grates to prevent sticking. Place the chicken thighs on the grill and cook for 5-7 minutes per side, flipping once, until the internal temperature reaches 165°F. During the last few minutes of grilling, baste the chicken with the simmered marinade for extra flavor. Remove from the grill and let rest for 5 minutes before serving.
Air Fryer Method: Preheat the air fryer to 375°F. Lightly grease the air fryer basket and place the marinated chicken in a single layer (cook in batches if needed). Air fry for 14-16 minutes, flipping halfway through, until the chicken reaches 165°F. In the last few minutes, brush the chicken with the simmered marinade for added flavor.
Oven Method: Preheat the oven to 400°F. Line a baking sheet with parchment paper or foil and lightly grease it. Arrange the chicken thighs in a single layer and bake for 20-25 minutes, flipping once, until the internal temperature reaches 165°F. In the last 5 minutes of baking, baste the chicken with the simmered marinade for extra moisture and flavor. Broil for 1-2 minutes at the end for a caramelized finish.
Serving Suggestions: Serve this Hawaiian-style grilled chicken with steamed rice, grilled pineapple, or a fresh tropical salad. Drizzle with extra sauce for even more flavor!