Preheat your oven to 400°F (200°C). This ensures the chicken and veggies cook evenly and get that perfect roasted flavor.
In a large mixing bowl, combine the soy sauce, sweet chili sauce, sriracha (if using), minced garlic, and cornstarch. Whisk together until smooth. The cornstarch will help thicken the sauce as it cooks, giving it a delicious glaze.
Add the chicken pieces to the bowl with the sauce. Toss until the chicken is well coated. Let it marinate for about 15 minutes while you prepare the veggies.
Chop the bell pepper into bite-sized pieces and rinse the broccoli florets and snap peas. You want everything to be similar in size for even cooking.
Spread the marinated chicken pieces onto a large baking sheet. Arrange the broccoli, bell pepper, and snap peas around the chicken. Drizzle any remaining sauce over the veggies for added flavor.
Place the baking sheet in the oven and bake for 20-25 minutes, or until the chicken is cooked through and the veggies are tender-crisp. If you like a little extra caramelization, you can broil it for an additional 2-3 minutes at the end.
Once done, remove the baking sheet from the oven. Sprinkle with sesame seeds if desired. Serve hot and enjoy your Baked Sweet Chili Chicken & Veggies over rice or noodles for a complete meal.