Heat another tablespoon of oil in the same pan. Add in a pinch of garlic and a pinch of ginger. Cook until fragrant. Add mushrooms. When cooked through set aside.
Add another tablespoon of oil and cook another pinch of garlic as well as ginger. Cook until fragrant and add about half the carrots and string beans. Keep tossing over medium high heat until cooked through and set aside. Repeat the process with the ginger, garlic, and the rest of the carrots and string beans and set aside.
Pour all the ingredients back into the pan to heat all thoroughly.
Mix together the sauce ingredients, excluding the arrowroot/ water combination. Add the sauce mixture to the pan and toss the stir fry in the sauce over medium heat.
After stirring together the arrowroot and water, turn off the heat under the pan and add the arrowroot mixture to the pan. You will see the sauce immediately thicken up as you stir it in. Taste it. I had to add a 2 more dashes each of coconut aminos and umeboshi, and about 1 more dash of Mirin. Serve immediately with the scallions sprinkled on top for garnish.