In a large Ziploc bag, combine flour, cornstarch, salt and garlic powder, shake to combine and set aside. In a medium bowl submerge chicken pieces in egg and toss a few times to fully coat.  Remove chicken pieces one by one and give a shake to remove excess egg and place in the bag with the flour mixture. Seal, shake and move around with your hands to evenly coat all the chicken pieces with the flour mixture.

In a large sauté pan, heat olive oil over medium high heat. Cook chicken until brown on all sides, about 12 to 15 minutes total. Add bell pepper and pineapple and sauté 5 minutes or until peppers begin to soften.

Meanwhile, in a small bowl, add pineapple juice, ketchup, soy sauce, vinegar and sugar and stir to combine. Add to skillet and cook 2 to 3 minutes or until sauce is thick and bubbly and evenly coats chicken and vegetables.

Drizzle sesame oil over warm cooked rice and toss with sesame seeds.  Serve alongside sweet and sour chicken.