In a mixing bowl, combine the brown sugar, soy sauce, minced garlic, grated ginger, lime juice, and olive oil to create a flavorful marinade. Place the boneless chicken breasts or thighs in a resealable bag and pour the marinade over them, ensuring they are well-coated. Seal the bag, refrigerate, and marinate for at least 30 minutes, or up to 2 hours for deeper flavor.

Preheat your grill to medium heat or your oven to 375°F (190°C). If using a grill, ensure the grates are clean and lightly oiled. For baking, prepare a baking dish by lining it with parchment paper or greasing it lightly.

If grilling, place the marinated chicken on the grill and cook for about 6-8 minutes per side, or until the internal temperature reaches 165°F (74°C). For baking, transfer the chicken to the preheated oven and bake for 25-30 minutes, ensuring it’s cooked through and juices run clear.

In the last few minutes of cooking, add fresh pineapple chunks directly onto the grill or around the chicken in the baking dish. Allow them to caramelize slightly for about 3-5 minutes.

After cooking, taste-test the pineapple chicken to ensure the flavor is balanced. Adjust sweetness and tang with extra lime juice or soy sauce if desired.

Once cooked, remove the chicken from the grill or oven and let it rest for a few minutes. Serve it over rice or quinoa, and garnish with fresh cilantro.