Pat chicken dry and season lightly with salt and pepper. Toss with cornstarch until fully coated.
Heat oil to 325°F (165°C). Fry chicken in batches for 6–8 minutes until cooked through but pale. Remove and drain.
Increase oil temperature to 375°F (190°C). Fry chicken again for 2–3 minutes until deeply golden and crispy.
In a saucepan, heat oil over medium heat. Sauté garlic and ginger briefly.
Stir in gochujang, honey, soy sauce, rice vinegar, and sesame oil. Simmer until thick and glossy.
Toss fried chicken in sauce until evenly coated. Serve immediately.