Whisk onion, soy sauce, brown sugar, garlic, sesame oil, sesame seeds, cayenne pepper, salt, and black pepper together in a bowl until marinade is smooth.
2 Brown (not fully cooked) chicken in a wok
3 Remove chicken and sauté desired vegetables
4 Remove vegetables and pour sauce into wok. Occasionally stir until it starts to simmer
5 Add chicken back into wok and mix for about 1 minute
6 Add sautéed vegetables to walk and mix then serve over rice