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 cornstarch and baking soda to the large bowl and whisk to combine. Add chicken to large bowl and turn with fingers to coat thoroughly. Cover with plastic wrap and set aside.
For the Dry Coat: Combine flour, cornstarch, baking powder, and salt in a large bowl. Whisk until homogeneous. Add reserved marinade and whisk until mixture has coarse, mealy clumps. Set aside.
To Fry Chicken: Heat 1 1/2 quarts peanut, vegetable, or canola oil in a large wok or Dutch oven to 350°F (177°C) 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 (163 to 191°C), until chicken is cooked through and very crispy, about 4 minutes. Transfer chicken to a paper towel-lined bowl to drain. Pour frying oil through a fine-mesh strainer set over a large heatproof bowl; allow to cool, then reserve for future frying.
For the Sauce and to Finish: Combine sugar, chicken stock, soy sauce, wine, vinegar, cornstarch, and sesame oil 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 chiles in a wok or 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 wok, making sure to scrape out any sugar or starch that has sunk to the bottom of bowl. Cook, stirring, until sauce boils and thickens, about 1 minute. Add scallion segments.
Add chicken to sauce, then toss, folding it with a wok spatula or silicone spatula until all pieces are thoroughly coated. Serve immediately with white rice.
Whisk, wok or Dutch oven (for frying) and large stainless-steel skillet (for sauce and finishing)
If desired, the sauce can be prepared up to 1 day in advance. Refrigerate in an airtight container, then warm before tossing with freshly fried chicken right before serving.
Shaoxing wine can be found in most Asian markets. If unavailable, dry sherry can be used in its place. If you can’t find boneless skinless chicken thighs, you can debone them yourself using this guide. If you can’t find whole dried chiles, substitute with 1/4 teaspoon crushed red pepper flakes.
This recipe is written to maximize efficiency with a wok: frying the chicken first, then making the sauce in the same wok (emptied of frying oil) and finally tossing it all together. This way, you only have to wash the wok once after making the full recipe. If desired, however, you can prepare the sauce in advance (up to 1 day ahead), then transfer it to an airtight container and refrigerate until ready to use; warm sauce before tossing with fried chicken right before serving.