Spray a wok with cooking spray. Heat over medium heat until hot. Add the onions and garlic powder. Stir-fry for 1 minute.
Add the pork and stir-fry for 4 minutes. Toss in all of the vegetables; stir-fry until the vegetables are tender, about 3 minutes.
Whisk the chicken broth, cornstarch, and soy sauce in a small bowl. Add this mixture to the wok and stir until the mixture boils and thickens.
Transfer the lo mein to a serving bowl and serve with the udon noodles.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy Stuart O'Keeffe, 2010