Make General Tso's Sauce: Add the sauce ingredients to a bowl and whisk well to combine. Set aside.

Make breading: Add cornstarch, flour, and salt and pepper to a large ziplock bag and shake to combine. Whisk egg whites in a separate bowl.

Coat chicken: Add chicken pieces to the egg whites and toss to coat. Spoon coated chicken pieces into the ziplock bag, allowing excess egg to drip back into the bowl. Shake the bag to coat chicken evenly in the cornstarch mixture.

Cook chicken: Heat a large skillet over medium-high heat. Add oil. Once oil is hot, add some of the chicken (it's best to cook the chicken in 2 or 3 batches, so it browns better). Cook the chicken 2-3 minutes on each side, until the coating is golden brown and the chicken is cooked through. Remove to a plate. Repeat until all of the chicken has cooked, and set aside on a plate.

Add sauce: Add the sauce to the pan and simmer until warm and thickened. Toss the chicken in the sauce just before serving.

Serve with hot cooked white or brown rice. Garnish with chopped green onions.