General Tsao Chicken

Marinade and Sauce:
1/2 cup hoisin sauce
1/4 cup white vinegar
3 tablespoons soy sauce
2 tablespoons cornstarch
1 1/2 cups water
4 boneless, skinless chicken breasts (about 1 1/2 pounds), cut into 1 inch pieces
1 tablespoon vegetable oil
4 garlic cloves, minced
2 tablespoons grated fresh ginger
1/2 teaspoon red pepper flakes

Coating and Frying
3 large egg whites
1 1/2 cup cornstarch
1/2 cup all purpose flour
1/2 teaspoon baking soda
4 cups vegetable oil

Direction:
For the marinade:
Whisk hoisin, vinegar, soy sauce, sugar, cornstarch, and water in the bowl. Combine 6 tablespoon of hoisin mixture with chicken in a zipper-lock bag, refrigerate for 30 minutes.
Heat oil in a large skillet over medium heat. Cook garlic, ginger and red pepper flakes until fragrant, about 1 minutes. Add 2 cups of the hoisin mixture, and simmer, whisking constantly until dark brown and thickened, about 2 minutes. Cover and keep the sauce warm.

For Coating and Frying:
Whisk egg whites in a shallow dish until foamy. Combine cornstarch, flour, baking soda, and the remaining of hoisin mixture in a second shallow dish until resemble coarse meal.
Remove chicken from the marinate, pat dry with paper towel. Toss the chicken with the egg whites until well coated, then dredge with flour mixture.
Heat oil until it reaches 350 degrees. Fry the chicken until golden brown. Transfer the chicken to paper towel-lined plate.

To Serve:
Warm the sauce over medium heat for 1 minute, add crisp chicken, toss to coat.
Serve over rice.