Combine the chopped chicken with the cornstarch and season with salt and pepper.
Heat the sesame oil in a nonstick pan over medium-high heat then add the chicken pieces. Stir-fry for 5 minutes. Add the minced garlic and ginger and sauté for 1 minute. Then add the vegetables and stir-fry for another 2 minutes.
Add the Hunan sauce and cook for 2 minutes.
Transfer the Hunan chicken to plates, garnish with sesame seeds, and serve.