Prep the chicken: Pat the chicken dry and slice it thinly across the grain. This helps it cook fast and stay tender.
Mix the sauce: In a small bowl, whisk soy sauce, oyster sauce, vinegar, honey, sesame oil, broth, cornstarch, and red pepper flakes.
Set aside.
Heat the pan: Place a large skillet or wok over medium-high to high heat. Add 1 tablespoon of oil and let it shimmer.
Sear the chicken: Add the chicken in a single layer. Season lightly with salt and pepper.
Cook 3–4 minutes, stirring once or twice, until just cooked through. Remove to a plate.
Cook sturdy veggies first: Add a little more oil if needed. Toss in broccoli, carrots, and onion.
Stir-fry 2–3 minutes.
Add quick-cooking veggies: Add bell pepper and snow peas. Stir-fry another 2 minutes until bright and crisp-tender.
Add aromatics: Push veggies to the sides. Add garlic and ginger to the center and stir for 30 seconds until fragrant.
Combine and sauce: Return chicken and any juices to the pan.
Give the sauce a stir and pour it in. Toss everything for 1–2 minutes until the sauce lightly thickens and coats the stir-fry.
Taste and adjust: Add a splash more soy for salt, vinegar for brightness, or heat if you like it spicy.
Serve: Top with green onions and sesame seeds. Serve over cauliflower rice to keep it low-calorie, or a small scoop of brown rice for extra fiber.