In a pot, combine rinsed quinoa with the water and bring to a boil. Reduce to a simmer, cover, and let sit for 15 minutes until all the water has been absorbed. Combine with cabbage, onions, and peppers in a large bowl.
In a small bowl, whisk together sauce ingredients. Pour over slaw mixture and stir well to combine. Cover, refrigerate and let cool for 1-2 hours until quinoa is cold and flavors have had a chance to blend together. Eat as a side or as a whole meal!