Preheat the oven to 425°F. Spray a sheet pan with nonstick cooking spray or brush with olive oil and place inside the oven as it is preheating.Pro Tip: Preheating the sheet pan gives the meat and vegetables a little sear when they go into the hot oven. You can also toss the vegetables with a bit of olive oil before putting them on the sheet pan, but it’s not necessary.
Cut chicken breasts into 1-inch cubes and pat dry.
In a medium bowl, whisk together soy sauce, honey, sesame oil, rice vinegar, garlic, ginger, and cornstarch. Divide sauce in half and set one half aside.Pro Tip: For more sauce, double the recipe, still using half to marinate the chicken and the other half to thicken on the stovetop.
Place chicken in the other half of the soy sauce mixture and toss to combine. Set aside to marinate for 30 minutes.
Wash and dry vegetables. Slice bell peppers into large pieces, discarding seeds and stems. Slice the green parts of two green onions and add to the vegetables.Pro Tip: Slice the bell peppers ahead of time and store them in the fridge in Ziploc bags for an even quicker prep time.
Drain marinating chicken and discard liquid.Pro Tip: It’s really important to drain off the liquid/marinade from the chicken. If there’s moisture going into the sheet pan, it makes everything mushy and muted in color.
Toss together chicken and all vegetables. Spread in a single layer on the heated sheet pan.
Bake for 15 to 20 minutes, stirring midway through cook time.
While stir fry mixture cooks in the oven, place reserved soy sauce mixture in a small saucepan. Whisk and heat over medium until the sauce thickens. Remove from heat.
When chicken is cooked (check the internal temperature to ensure it has reached 165°F, remove sheet pan from oven.
Drizzle thickened sauce over the sheet pan’s contents and sprinkle liberally with sesame seeds.
Serve immediately, garnished with more sliced green onions and rice, if desired.