Place flour and cornstarch in a shallow dish or pie plate. Add a generous pinch of salt. Stir.
Whisk eggs in shallow dish.
Dip chicken pieces in egg mixture and then flour mixture. Place on plate.
Heat 2 -3 inches of oil in a heavy-bottomed pot over medium-high heat. Using a thermometer, watch for it to reach 350 degrees.
Working in batches, cook several chicken pieces at a time. Cook for 2 - 3 minutes, turning often until golden brown. Place chicken on a paper-towel-lined plate. Repeat.
Toss chicken with orange sauce. You may reserve some of the sauce to place on rice. Serve it with a sprinkling of green onion and orange zest, if so desired.