Place the chicken pieces in a medium bowl with 1 tablespoon of the soy sauce, salt, and pepper. Stir to coat. Sprinkle 1 teaspoon of the cornstarch over the top and stir once more. Set aside.
In a separate medium bowl, whisk together the remaining 1/4 cup soy sauce, water, honey, rice vinegar, garlic, ginger, red pepper flakes, and remaining 2 teaspoons cornstarch until smoothly combined. Set aside.
Heat a large nonstick skillet or wok over medium-high heat. Spray the pan with cooking oil. Once the oil is simmering, add the chicken pieces in an even layer. Let it cook undisturbed for 2 to 3 minutes then turn the chicken pieces and cook another 2 to 3 minutes.
Add the broccoli and carrots to the pan and toss to combine with the chicken. Cook 5 minutes then add the snap peas along the sauce.
Cook until the sauce thickens and appears glossy, about 2 to 4 minutes. Stir in half of the green onions. Toss to combine cooking another minute before removing from the heat.
Serve hot over cooked rice topped with the remaining half of green onions.
Notes
This teriyaki stir-fry cooks very quickly once you start, so be sure to chop up all of your chicken and vegetables before you turn on the stove.
Don’t overcrowd the pan with chicken and vegetables, or they will steam instead of sear. You may need to cook the meal in batches to avoid this.
Don’t constantly stir the chicken, or it won’t sear properly. Give it time to cook before flipping or stirring it.