Step 1: In a medium bowl, whisk together the egg and 2 tablespoons of soy sauce. Add the chicken pieces and toss to coat thoroughly. Let marinate for 10 minutes.
Step 2: Place 1/2 cup of cornstarch in a shallow dish. Remove chicken from the marinade and dredge each piece in cornstarch until heavily coated. Set aside on a wire rack for 5 minutes.
Step 3: Heat 2 inches of vegetable oil in a wok or deep pot to 350°F. Fry the chicken in batches for 4-5 minutes until golden and crispy. Drain on paper towels.
Step 4: In a separate small bowl, whisk together the chicken broth, 1/4 cup soy sauce, rice vinegar, hoisin sauce, and sugar.
Step 5: Heat 1 tablespoon of oil in a large skillet over medium-high heat. Add the ginger, garlic, and dried chilis, sautéing for 30 seconds until fragrant.
Step 6: Pour in the sauce mixture and bring to a simmer. Whisk in the cornstarch slurry and cook until the sauce thickens and becomes glossy.
Step 7: Add the fried chicken to the skillet and toss quickly to coat every piece in the sauce. Serve immediately over rice, garnished with green onions and sesame seeds.