Heat 1 quart of oil in lg deep skillet over med-high heat. Toss chicken pieces w/ beaten egg. Place panko crumbs in a shallow bowl. One at a time, coat chicken pieces w/ crumbs.
Fry chicken in oil until golden brown. Place on paper towels to drain. Keep warm. Heat 1 tbsp oil in anothe skillet or wok. Place over high heat. Stir into skillet, the garlic, ginger, green onions and red flakes. Cook and stir until garlic turns brown.
Pour in soy sauce, vinegar, and brown sugar. Bring to a boil. Dissolve cornstarch in water. Stir into boiling sauce to thicken. Cook 45 seconds. Toss chicken w/ sauce. Serve over rice.