Pat chicken dry, then season evenly with salt and pepper.
Combine cornstarch and flour in a shallow bowl. Toss chicken to coat and shake off excess.
Heat oil in a large skillet to about 350°F over medium-high heat.
Fry chicken in batches until crisp and golden, 4–5 minutes. Drain on a rack or paper towels.
Whisk orange juice, zest, soy sauce, rice vinegar, brown sugar, honey, garlic, ginger, red pepper, and sesame oil in a saucepan.
Bring sauce to a simmer over medium heat. Stir cornstarch with water, then whisk slurry into the pan.
Cook, stirring, until the sauce thickens and turns glossy, 1–2 minutes.
Add fried chicken to the sauce and toss until every piece is coated.
Top with scallions and sesame seeds. Serve hot over steamed rice.