Place the water, vinegar, vegetable oil, sugar, garlic, ginger, crushed red pepper flakes and Tamari (eyeball it) in a small saucepot over medium-high heat. Bring up to a bubble and simmer for one minute. Remove the saucepot from the heat and discard the garlic and ginger.
Place the sliced onions in a salad bowl and pour the hot mixture over them. Let sit until cool.
Add the cucumbers and spinach to the salad bowl, toss to combine and season with salt and pepper, to taste.
This is one of many “Yum-o!” recipes – it’s good and good for you. To find out more about Yum-o!, Rachael’s nonprofit organization, go to www.yum-o.org.