1. In a large sauté pan, heat the oil over medium heat. Add the scallions and garlic, and sauté until fragrant, about 1 minute. Add the bell pepper and snap peas, and sauté until just tender, 2 to 3 minutes.
2. Add the chicken and cook until it is golden and fully cooked and the vegetables are tender, 4 to 5 minutes.
3. Add the soy sauce, rice vinegar, Sriracha (if using) and sesame seeds; toss well to combine. Allow the mixture to simmer for 1 to 2 minutes.
4. Stir in the cilantro, then garnish with a sprinkle of extra cilantro and sesame seeds. Serve immediately.
