In a large Ziplock bag, mix 1 cup cornstarch, black pepper, ginger, nutmeg, thyme, sage, and paprika. Seal and shake up to mix.
Cut the chicken into 1" cubes and add to the bag of corn starch, seal and toss chicken until all the pieces are well coated. Remove chicken from bag, making sure to remove any excess cornstarch
Place in your air fryer and cook according to the manual that comes with your air fryer. I set mine at 390°F for 24 minutes, tossing the chicken halfway through. Make sure chicken is cooked to an internal temperature of 165°F.
Make the sauce while the chicken is cooking.
Whisk together 1/4 cup water and 2 tablespoons of cornstarch and set aside.
In a pan over medium heat, whisk together orange juice, sugar, soy sauce, vinegar, garlic, ginger, and chili flakes. Simmer for 3 minutes.
Whisk in cornstarch slurry, cooking for 5 minutes or until thickened.
Remove from heat and stir in the green onions and orange zest.
Toss cooked chicken into the sauce and serve.