Combine 4 tablespoons cornstarch, 1 tbsp soy sauce, 1 tbsp rice wine and the egg white in a bowl. Add chicken and stir to coat.
Combine the remaining soy sauce and rice wine, water, hoisin and rice wine vinegar in a small bowl. Set aside.
Heat 2 tbsp oil in a wok or large cast-iron skillet over high heat. Add the chicken. Cook without turning, breaking up stuck-together pieces, until golden on the bottom, approximately 2 minutes. Stir; continue cooking until golden on all sides, 1 to 2 minutes more. Transfer to a plate.
Add the remaining 1 tablespoon oil, scallions and garlic. Cook, stirring, until fragrant, about 15 seconds. Add peas, stirring often, until bright green, 2 to 3 minutes. Add the reserved sauce mixture, stirring until thick, about 1 minute. Return the chicken to the pan, stirring until heated through, about 1 minute more. Enjoy alone or serve with rice or noodles.