Panda Express Orange Chicken (Copycat)

Name: Panda Express Orange Chicken (Copycat)
Prep time: 45 min
Cook time: 15 min
Total time: 1 h
Cuisine: Asian
Ingredients: 2 pounds boneless skinless chicken breasts (cut into 1-inch pieces); 1/2 cup all-purpose flour; 1/2 cup cornstarch; 1 teaspoon paprika; 1/2 teaspoon fresh ground black pepper; 1 teaspoon garlic salt; 1/2 teaspoon onion powder; 1/2 cup whole milk; 1 large egg; 1 tablespoon vegetable oil; Vegetable oil (for frying); 1 tablespoon sesame oil; 1 teaspoon red chili paste; 1 tablespoon minced garlic (about 3 cloves); 1 tablespoon minced fresh ginger (about 1-inch piece); 1 tablespoon light soy sauce; 1 tablespoon orange zest; 1/4 cup rice vinegar; 1/2 cup granulated sugar; 1/2 cup fresh orange juice; 1 tablespoon cornstarch; 2 green onions (thinly sliced (optional garnish))