1 large egg
1 pound boneless, skinless chicken thighs, cut into 1-inch pieces
1/4 teaspoon salt
pinch of white pepper
5 to 6 tablespoons cornstarch, divided
1 1/2 tablespoons dark soy sauce
1 1/2 tablespoons hoisin
2 teaspoons white rice vinegar
2 teaspoons Shaoxing wine
3/4 teaspoon red chili oil
1 1/2 teaspoons minced garlic
1 tablespoon peeled and minced ginger
2 teaspoons sugar
3 1/2 cups peanut oil
8 small dried red chiles, preferably Thai chiles
5 scallions, white parts only, sliced 1/2-inch thick