Season chicken with salt and pepper.
Heat oil in a large skillet over medium-high heat. Add chicken in a single layer and cook until golden and cooked through. Remove and set aside.
Lower heat to medium. Add garlic and ginger to the pan; cook until fragrant (about 30 seconds).
Stir in gochujang, soy sauce, honey, rice vinegar, and sesame oil.
Add cornstarch slurry and simmer until sauce thickens and becomes glossy.
Return chicken to the pan and toss until fully coated.
Cook 2–3 minutes until sauce clings to chicken.
Garnish and serve immediately.