Preheat your oven to 350°F (175°C). Slice the bell peppers in half, remove seeds and membranes, and cook the rice according to package instructions.

Marinate chicken with teriyaki sauce, pineapple juice, minced garlic, and grated ginger in a bowl for at least 1 hour.

Cook marinated chicken in a skillet over medium-high heat for 6-8 minutes per side until browned and reaches internal temperature of 165°F (74°C). Add pineapple chunks in the last minute.

Chop the cooked chicken and mix it with cooked rice, diced red onion, and teriyaki sauce until well combined.

Stuff each halved bell pepper with the chicken and rice mixture, pack slightly, and place upright in a baking dish. Optionally, sprinkle cheese on top.

Bake in the preheated oven for 20-25 minutes until the peppers are tender and the filling is heated through.

Remove from oven, let cool slightly, and garnish with sliced green onions and sesame seeds before serving.