Make the batter: in a large bowl, combine the cornstarch, flour, egg, water, 1 tablespoon vegetable oil, salt, and pepper to taste until smooth.
Add the chicken pieces, make sure they are all covered with batter, cover with plastic wrap, and refrigerate for 30 mins.
Into a large skillet, pour about one inch of oil and heat it over medium-high heat until it sizzles when you drop a bit of batter into it.
Shake off any excess batter from the chicken pieces and fry them until brown on both sides. You might need to do this in batches. Transfer to a plate lined with a paper towel and keep warm.
Make the glaze: in a medium sized skillet or saucepan, heat the sesame seed oil and saute the minced garlic and grated ginger until fragrant, about 30 seconds. Add the orange juice, brown sugar, vinegar, soy sauce, and sriracha. Simmer until the sugar has dissolved.
In a small bowl mix the cornstarch with water and add it to the sauce. Cook until slightly thickened.
Mix the chicken pieces into the glaze and continue cooking until all the pieces are well coated with the glaze and are heated through. Serve over rice with sesame seeds and sliced green onions on top.