In a medium bowl, whisk together the cornstarch, gluten free flour blend, and salt. In a separate bowl, beat the eggs. Dip each chicken piece into the egg, then toss in the cornstarch mixture until evenly coated. Place the coated pieces on a sheet pan.
Heat about 1 inch of vegetable oil in a large deep skillet or wok over medium-high heat to 350 degrees F. Fry the chicken pieces in batches for 4 to 5 minutes, turning occasionally, until golden and cooked through. Transfer to a wire rack and set aside.
While the chicken fries, prepare the sauce. In a small bowl, whisk together the orange juice, tamari, rice vinegar, honey, orange zest, garlic, ginger, and red pepper flakes.
Drain all but 1 tablespoon of oil from the skillet. Pour in the sauce mixture and bring it to a simmer over medium heat, stirring occasionally, for about 2 minutes.
Stir the cornstarch slurry and pour it into the simmering sauce. Cook for 1 to 2 minutes, stirring constantly, until the sauce thickens and turns glossy.
Add the fried chicken back into the skillet and toss to coat every piece in the sauce. Drizzle with sesame oil, then transfer to a serving plate and garnish with sesame seeds and sliced green onions. Serve immediately over steamed rice.