Prep the chicken: Pat the chicken dry with paper towels. Cut into 1-inch pieces. Season with salt and pepper, then toss with 1 tablespoon cornstarch to lightly coat.
Make the sauce: In a small bowl, whisk together honey, soy sauce, rice vinegar, sesame oil (if using), remaining 1 tablespoon cornstarch, and red pepper flakes.
Set aside.
Heat the pan: Place a large skillet over medium-high heat. Add the oil and let it get hot until shimmering.
Sear the chicken: Add the chicken in a single layer without crowding. Cook 3–4 minutes without moving, then flip and cook another 3–4 minutes until browned and cooked through.
Work in batches if needed to keep a good sear.
Add the garlic: Reduce heat to medium. Push chicken to the sides and add minced garlic to the center. Cook 30 seconds until fragrant, stirring so it doesn’t burn.
Sauce it up: Pour in the sauce and stir to coat the chicken.
Simmer 1–2 minutes, stirring, until the sauce thickens and becomes glossy.
Taste and adjust: Add a pinch of salt, more honey for sweetness, or a splash of vinegar for brightness, if needed.
Finish and serve: Remove from heat. Garnish with sliced green onions and sesame seeds. Serve over hot rice or noodles, or alongside steamed broccoli.