1 pound boneless, skinless chicken thighs, cut into 1/2- to 3/4-inch chunks
For the Dry Coating
1/2 cup flour
1/2 cup cornstarch
1/2 teaspoon baking powder
1/2 teaspoon kosher salt
For the Sauce:
3 tablespoons dark soy sauce
2 tablespoons Shaoxing wine
2 tablespoons Chinese rice vinegar or distilled white vinegar
3 tablespoons homemade or store-bought low-sodium chicken stock
4 tablespoons sugar
1 teaspoon roasted sesame seed oil
1 tablespoon corn starch
2 teaspoons peanut, vegetable, or canola oil
2 teaspoons minced garlic (about 2 medium cloves)
2 teaspoons minced fresh ginger (about one 1-inch piece)
2 teaspoons minced scallion bottoms (about 1 scallion), plus 6 to 8 scallions, white parts only, cut into 1-inch lengths
8 small dried red Chinese or Arbol chilies
1 1/2 quarts peanut, vegetable, or canola oil for deep frying
Steamed white rice for serving
For the Marinade:
Beat egg whites in a large bowl until broken down and lightly foamy. Add soy sauce, wine, and vodka and whisk to combine. Set aside half of marinade in a small bowl. Add baking soda and corn starch to the large bowl and whisk to combine. Add chicken tp large bowl and turn with fingers to coat thoroughly. Cover with plastic wrap and set aside.
For the Dry Coat:
Combine flour, corn starch, baking powder, and 1/2 teaspoon salt in a large bowl. Whisk until homogenous. Add reserved marinade and whisk until mixture has coarse, mealy clumps. Set aside.
For the Sauce:
Combine soy sauce, wine, vinegar, chicken stock, sugar, sesame seed oil, and cornstarch in a small bowl and stir with a fork until cornstarch is dissolved and no lumps remain. Set aside.
Combine oil, garlic, ginger, minced scallions, and red chilies in a large skillet and place over medium heat. Cook, stirring, until vegetables are aromatic and soft, but not browned, about 3 minutes. Stir sauce mixture and add to skillet, making sure to scrape out and sugar or starch that has sunk to the bottom. Cook, stirring, until sauce boils and thickens, about 1 minute. Add scallion segments. Transfer sauce to a bowl to stop cooking, but don't wipe out skillet.
Heat 1 1/2 quarts peanut, vegetable, or canola oil in a large wok or Dutch oven to 350°F and adjust flame to maintain temperature.
Working one piece at a time, transfer chicken from marinade to dry coat mixture, tossing in between each addition to coat chicken. When all chicken is added to dry coat, toss with hands, pressing dry mixture onto chicken so it adheres, and making sure that every piece is coated thoroughly.
Lift chicken one piece at a time, shake off excess coating, and carefully lower into hot oil (do not drop it). Once all chicken is added, cook, agitating with long chopsticks or a metal spider, and adjusting flame to maintain a temperature of 325 to 375°F, until chicken is cooked through and very crispy, about 4 minutes. Transfer chicken to a paper towel-lined bowl to drain.
Add chicken to empty skillet and return sauce to skillet. Toss chicken, folding it with a rubber spatula until all pieces are thoroughly coated. Serve immediately with white rice.
Shaoxing wine can be found in most Asian markets. If unavailable, dry sherry can be used in its place.
If you can't find whole dried chilies, substitute with 1/4 teaspoon crushed red pepper flakes.