In a large bowl, whisk together pineapple juice, soy sauce, brown sugar, minced garlic, and grated ginger until well combined.
Add chicken thighs to the marinade, ensuring each piece is coated. Cover and refrigerate for at least one hour or overnight for deeper flavor.
Heat your grill to medium-high (about 400°F).
Grilling
Remove chicken from marinade (reserve marinade). Grill thighs for approximately six minutes per side or until they reach 165°F internal temperature, basting with reserved marinade during the last few minutes.
Transfer grilled chicken to a platter and let it rest for five minutes.
Serving
Garnish with chopped green onions and serve with steamed rice or salad.
Notes
For best flavor, marinate chicken thighs overnight. Use fresh ingredients where possible. The marinade can also be used with pork or firm tofu for vegetarian options. Feel free to add herbs and spices for variation.