Prep the chicken: Pat the chicken dry and slice into thin, bite-size strips. Season lightly with salt and pepper. Thin slices cook quickly and stay tender.
Make the teriyaki sauce: In a bowl, whisk together soy sauce, mirin or rice vinegar, brown sugar or honey, sesame oil, and water or broth.
In a separate small bowl, stir the cornstarch with 2 tablespoons of water to make a slurry. Set both aside.
Prep the vegetables: Cut everything into similar sizes so they cook evenly. Keep tender veggies like bell pepper and snap peas separate from denser ones like broccoli and carrot.
Heat the pan: Set a large skillet or wok over medium-high heat.
Add 1 tablespoon of oil and swirl to coat. The pan should be hot enough that the oil shimmers.
Cook the chicken in batches: Add half the chicken in a single layer. Sear for 2–3 minutes per side until golden and mostly cooked through.
Transfer to a plate. Repeat with remaining chicken, adding oil if needed. Don’t overcrowd the pan or it will steam instead of sear.
Sauté the aromatics: Lower heat to medium. Add a small splash of oil if the pan is dry.
Stir in garlic and ginger for 30 seconds until fragrant. Keep them moving so they don’t burn.
Stir fry the vegetables: Add broccoli and carrot first. Cook 2–3 minutes, stirring often. Then add onion, bell pepper, and snap peas.
Cook another 2–3 minutes until crisp-tender. A little bite is good—they’ll soften more once sauced.
Add chicken and sauce: Return chicken and any juices to the pan. Pour in the teriyaki mixture (without the slurry). Let it bubble for 1 minute.
Stir the cornstarch slurry, then drizzle it in while stirring. Simmer 1–2 minutes until the sauce thickens and coats everything.
Taste and adjust: For more sweetness, add a splash of honey. For salt, add a dash of soy sauce.
For heat, sprinkle red pepper flakes. Finish with a few drops of sesame oil if you like a deeper aroma.
Serve: Spoon over warm rice or toss with noodles. Garnish with sesame seeds and sliced green onions.
Serve immediately while it’s glossy and hot.