Preheat oven to 325° F.
Heat large skillet over high heat until very hot. Add first 4 ingredients and stir-fry until pork is brown and onion is tender, about 5 minutes. Mix in bok choy, red bell pepper and mushrooms and stir-fry until bell pepper is crisp-tender, about 5 minutes. Remove from heat source.
Wrap tortillas in foil and place in oven for 8 minutes or until warm.
Return stir-fry to high heat source and add bean sprout, sake hoisin and soy sauce and stir-fry until bean sprouts are crisp-tender, about 5 minutes.
Remove tortilla from oven. Divide pork mixture among tortillas and roll up to enclose pork mixture. Serve immediately.
Servings: