In a small bowl, whisk together pineapple juice, honey, soy sauce, rice vinegar, ginger, minced garlic, and cornstarch until smooth. Set aside.

Cut chicken into 1-inch pieces, season with garlic powder and pepper, and coat with cornstarch.

Heat olive oil in a skillet over medium-high heat and cook the chicken until golden brown on both sides.

Add pineapple chunks to the skillet and sauté for 1 minute to caramelize.

Add chopped red bell pepper and sliced onion, stir-fry for about 3 minutes until tender-crisp.

Combine cooked chicken with sautéed vegetables and pour in the sauce, cooking until bubbling.

Serve hot over rice or noodles, garnishing with scallions or sesame seeds if desired.