In a large bowl, mix together the flour, cornstarch, baking powder, egg, and salt. Add water and whisk until smooth.
Add the chicken pieces to the batter, mixing together so all the pieces are coated. Leave the chicken in the batter until you are ready to fry.
Frying Sesame Chicken
In a wok or saucepan, add enough oil to fry. Should be at least 2 to 3 inches deep. Heat oil until hot, around 350°F.
Slowly add the battered chicken, one piece at a time, and fry in small batches. Fry for about 5 minutes until golden brown and crispy. Don't allow the pieces to stick together while frying, constantly turning the chicken.
Remove from wok onto a paper towel lined plate. Repeat the process until the chicken is cooked.
Honey Sesame Sauce
Mix together the honey, Chinese Cooking Wine, Rice Wine Vinegar, Soy Sauce, Sesame Oil and water. Set aside.
In a glass, mix together the cornstarch and water and make a slurry. Set aside.
Heat 2 tablespoons of oil in a wok and quickly fry the chopped garlic, no more than 30 seconds. Add the honey sauce and heat until it bubbles. Add the cornstarch slurry and cook it for about 1-2 minutes, until sauce thickens.
Making Sesame Chicken
Toss the crispy chicken pieces in the hot honey sesame sauce until fully coated. Serve immediately over rice. Sprinkle with roasted sesame seeds and chopped green onions.