In a bowl, whisk together the ginger, soy sauce, rice vinegar, teriyaki sauce, black pepper, and poppy seeds.
Heat sesame oil over medium-high heat in a large skillet or wok. Stir in the garlic and onion, and cook 2 to 3 minutes, until they are just starting to brown. Drop in the chicken, and cook and stir for 5 minutes, until no longer pink. Pour in the ginger-soy sauce mixture, bring to a boil, and mix in the vegetables. Continue to cook and stir 5 to 7 minutes, until the vegetables are tender. Serve hot.