Prepare the rice according to package instructions.
Heat sesame oil in a large skillet over medium-high heat.
Sauté the onion and bell pepper until softened, about 5 minutes.
Add minced garlic and cook for an additional minute.
Season the chicken with salt and pepper before adding it to the skillet.
Add the chicken to the skillet, cooking until browned on all sides, about 8 minutes.
Pour in the soy sauce and add the pineapple; stir to combine.
Cover and simmer for 10-15 minutes until the chicken is cooked through.
Fluff the rice and add it to the skillet, mixing well to combine.
Garnish with sliced green onions before serving.