Heat oil in a large skillet over medium-high heat.

Add cubed chicken to the skillet.

Cook and stir until the chicken is well browned on all sides.

Add green and red pepper strips to the skillet.

Cook and stir for 1 to 2 minutes until the peppers are slightly softened.

In a small bowl, mix cornstarch and lite soy sauce until smooth.

Add the cornstarch mixture to the skillet with the chicken and peppers.

Pour in the pineapple chunks (with juice), vinegar, brown sugar, ground ginger, and garlic powder.

Stir well to combine all the ingredients.

Bring the mixture to a full boil, stirring constantly.

Reduce heat and simmer until the sauce has thickened to your preference.

Prepare instant brown rice according to package directions.

Serve the sweet and sour chicken over the prepared rice immediately.