For the Chicken:
- 1/2 cup hoisin sauce
- 1/4 cup white vinegar
- 3 tablespoons soy sauce
- 3 tablespoons sugar
- 2 tablespoons cornstarch
- 1 1/2 cups water
- 1 1/2 pounds (about 4) boneless, skinless chicken breasts, cut into 1-inch pieces
- 1 tablespoon vegetable oil
- 4 garlic cloves, minced
- 2 tablespoons grated fresh ginger
- 1/2 teaspoons red pepper flakes
For Coating and Frying:
- 3 large egg whites
- 1 1/2 cups cornstarch
- 1/2 cup unbleached all purpose flour
- 1/2 teaspoon baking soda
- 4 cups vegetable oil
- 1-2 green onions, thinly sliced
- 1 teaspoon white sesame seeds
- In a large bowl, combine hoisin, vinegar, soy sauce, sugar, cornstarch and water in a bowl. Transfer 6 tablespoons of this mixture in a ziptop storage bag and add the chicken; refrigerate for 30 minutes. Set aside the remaining mixture.
- While the chicken is marinating, heat oil in a large skillet over medium heat until shimmering. Sauté the garlic, ginger and red pepper flakes until fragrant, about 1 minute. Add 2 cups of the hoisin mixture and simmer, whisking constantly, until the mixture is dark brown and thickened. Remove from heat, cover.
- To prepare the chicken for coating and frying, in a shallow bowl, whisk the egg whites until foamy; set aside.
- In a second shallow dish, combine the cornstarch, flour, baking soda, and remaining hoisin marinade; mix until it resembles coarse meal.
- Preheat oven to 200 degrees F. Set a wire rack in a rimmed baking sheet; set aside. Heat the oil in a Dutch oven over medium high heat until the oil registers 350 degrees.
- Remove the chicken from the marinade and pat dry with paper towels. Toss half the chicken into the egg whites until well coated, then dredge the chicken in the cornstarch mixture, pressing to adhere. Transfer the coated chicken to a plate and repeat with the remaining chicken.
- Fry half the chicken until golden brown, about 3 minutes, turning each piece halfway through cooking. Transfer chicken to prepared baking sheet and place in oven. Bring oil back to 350 degrees and repeat with remaining chicken pieces.
- Rewarm the sauce over medium heat until simmering add the fried chicken pieces, tossing to coat. Garnish with green onions and sesame seeds.