Heat 2 tablespoons of oil in a large 12-inch skillet over medium heat. Once the oil shimmers, add chicken pieces in a single layer. Cook for 6-8 minutes, turning occasionally, until golden brown and internal temperature reaches 165°F with no pink remaining. Transfer chicken to a plate and set aside.

In the same skillet, add minced garlic and saute for about 30 seconds until fragrant but not browned. Pour in soy sauce, pineapple juice, honey, and vinegar. Stir everything together and bring to a gentle simmer for about 1 minute.

Stir the cornstarch mixture, then slowly pour it into the simmering sauce while stirring constantly to prevent lumps. Cook for 2-3 minutes until the sauce thickens and develops a shiny, syrupy appearance. Return cooked chicken to the skillet, then add pineapple chunks and diced red bell pepper. Toss everything together to coat evenly in sauce.

Keep skillet on medium-low heat and gently fold in cooked rice, stirring carefully to combine without mashing the grains. Let everything warm through for about 2 minutes, stirring occasionally until the rice absorbs some sauce.

Remove from heat and immediately garnish with chopped green onions and sesame seeds. Add crushed red pepper if desired. Serve hot.