Mix flour, salt, pepper, and garlic powder in bowl.
Whisk egg and milk in second bowl.
Heat enough oil in large frying pan to cover the bottom of the pan about ½" deep on medium heat, or until water sizzles when flicked into pan.
Dredge chicken in flour mixture, then egg mixture, then flour mixture again.
Space chicken apart in pan and fry until golden brown on bottoms/side, flipping once, in batches. Don't crowd the pan. Place chicken on cooling rack. Repeat process with remaining chicken.
While second batch of chicken is frying, make sauce: saute garlic and ginger in sesame oil until fragrant.
Add orange juice, soy sauce, sugar, vinegar, and sriracha. Stir on med until it has reached a low simmer until slightly thickened.
Add cornstarch dissolved in water, whisk until desired consistency is reached.
Steam broccoli until crisp-tender.
Cook enough rice for 5 servings.
Combine fried chicken and sauce, serve over rice and broccoli, garnish with green onions.