To Prep Combine the sauce ingredients in to a medium bowl. Season the cut mushrooms with 1 tbsp of the sauce.Prepare the sweet potato noodles as per the packet instructions and mix in 3 tbsp of the sauce.Blanch the spinach in boiling water until it has just started to wilt before removing it from the water and shocking it with cold water to stop the cooking process. To Cook In a non-stick pan, stir fry the noodles over medium heat until they become translucent. Transfer the noodles to a large mixing bowl before adding the vegetable oil to the pan and stir frying the onions.Cook the onions until they start to become translucent, then adding the spring onions and continuing to cook for another minute.Transfer the onions and spring onions in to the mixing bowl.Cook the carrots on the pan for about 2 minutes or until they softened and transfer them in to the mixing bowl. Finally, stir fry the marinaded mushrooms in the pan for roughly 2 to 3 minutes before once again transferring them in to the mixing bowl. Before serving, add the spinach to the mixing bowl and gently mix the all of the ingredients. Season with soy sauce or sugar to taste and serve!