Sauce: Shake up all the ingredients in a jar or stir with whisk in a bowl.
Udon: Heat your wok or pan over medium high heat. Add oil. Add the noodles and enough sauce to coat. Stir-fry and then leave for a minute or two to caramelize. Microwave your frozen veggies and drain any water (important to drain the water or it will make the sauce runny).
Add the veggies. Combine and let cook for a couple more minutes until everything is covered in sauce and nice and hot.
Remove from heat. Add toppings and enjoy!