Pour 1 to 2 inches of canola oil in a small deep fryer or heavy bottomed pot and heat to 375 degrees F.*
In a large bowl combine the sesame oil, egg, 3 tbsp soy sauce and 1/3 cup corn starch until a thin batter forms. Toss in the chicken pieces and let sit for a few minutes while the oil heats up. Fry the chicken in batches and drain on a paper towel lined plate. Meanwhile, prepare the sauce.
For the Sauce:
Combine the orange zest, orange juice, 3 tbsp soy sauce, 3 tbsp water, 1/3 cup sugar, 1/3 cup rice wine vinegar (or dry sherry), 1/3 cup chicken broth and 2 tbsp corn starch in a bowl and set aside.
Once chicken is finished cooking, heat 1 tsp canola oil in a large wok or skillet over medium high heat. Toss in the ginger, garlic and red pepper flakes (if using) and stir until fragrant, about 30 seconds. Pour in the sauce and cook over medium heat until thickened, stirring occasionally.
Once thickened (about 3 to 4 minutes) add the chicken to the wok and stir to coat with sauce. Garnish with sliced green onions and orange slices and serve over hot steamed rice if desired. Enjoy!
*If you don't have a deep fryer or a heavy bottomed pot, add a few tablespoons of canola oil to a skillet with high edges and cook the chicken on all sides until browned and crispy. Drain on paper towel lined plates.