In a small bowl, combine the juice, zest, soy sauce, sugar, garlic, vinegar, ginger and cornstarch together and whisk until sugar dissolved.
Heat oil in large frying pan or wok over medium-high heat. Once a drop of water sizzles in the oil, add the chicken to the oil, stirring constantly. After the chicken has been browned on each side, about 3-4 minutes, remove chicken to a large plate.
Add the sauce to the skillet and bring to a boil. Turn to a simmer and return chicken to pan to finish cooking in the sauce, about 5 minutes.
Serve over steamed rice or quinoa and garnish with green onion slices.