Heat the vegetable oil in a large skillet or wok over medium-high heat. Add the chicken pieces and cook until browned and cooked through, about 5-7 minutes. Remove the chicken from the skillet and set aside.
In the same skillet, add the sliced bell peppers, broccoli, and snap peas. Stir-fry the vegetables for about 3-4 minutes until they are tender-crisp.
Add the minced garlic and ginger to the skillet and stir-fry for an additional 1 minute until fragrant.
In a small bowl, whisk together the soy sauce, honey, rice vinegar, sriracha, sesame oil, and red pepper flakes (if using). Pour the sauce over the vegetables in the skillet.
Return the cooked chicken to the skillet and toss everything together to coat in the sauce. Cook for another 2-3 minutes until heated through.
Serve the stir fry over cooked rice or quinoa, garnished with sliced green onions and sesame seeds.