Prep the chicken: Slice the chicken into thin strips.
Toss with 1 tablespoon soy sauce and 1 tablespoon cornstarch. Set aside while you prepare the vegetables.
Mix the sauce: In a small bowl, whisk 2 tablespoons soy sauce, oyster or hoisin (if using), rice vinegar, sesame oil, honey, and chicken broth. Stir in 1 teaspoon cornstarch until smooth.
Adjust sweetness or salt to taste.
Heat the pan: Place a large skillet or wok over medium-high heat. Add 1 tablespoon oil and swirl to coat. You want it hot before the chicken hits the pan.
Sear the chicken: Add chicken in a single layer.
Cook 3–4 minutes, stirring once or twice, until golden and cooked through. Remove to a plate. Do not crowd the pan; work in batches if needed.
Cook the tough veggies: Add 1 teaspoon oil if the pan is dry.
Toss in broccoli and carrots. Stir fry 2–3 minutes until they begin to soften but still have crunch.
Add quick-cooking veggies: Add bell pepper, zucchini, and snap peas. Stir fry another 2–3 minutes until bright and crisp-tender.
Aromatics go in: Push veggies to the sides.
Add 1 teaspoon oil to the center, then add garlic, ginger, and the white parts of the green onions. Stir 30 seconds until fragrant.
Combine and sauce: Return the chicken and any juices to the pan. Pour in the sauce and toss everything together.
Cook 1–2 minutes until the sauce thickens and coats the stir fry.
Finish and serve: Add red pepper flakes or sriracha if you like heat. Sprinkle with sesame seeds and green onion tops. Serve over brown rice, quinoa, or cauliflower rice.