Thinly slice the chicken breasts, and lightly sprinkle with salt and pepper.
In a small bowl, whisk together the soy sauce, rice wine vinegar, cornstarch and 1/4 cup water.
Heat the canola oil over high heat in a wok. Add the chicken in one layer and cook until browned on one side, about 2 minutes. Stir to flip; cook on the reverse side until browned and cooked through. Remove the chicken to a plate. To the wok, add the red pepper flakes, ginger, garlic, broccoli, onions, snow peas and bean sprouts; add a splash of water if the pan is dry. Stir fry for a minute or two, then add the reserved chicken and any juices it may have released.
Add the soy sauce mixture to the wok, stir to combine, and cook until the sauce reaches the consistency of a glaze, about 2 minutes. Serve immediately, by itself or with rice.