Cut chicken into 1" pieces and place inside of a large bowl with arrowroot and a big pinch of salt and pepper. Toss to coat the chicken fully.
Heat oil in a large, heavy skillet. Once hot, brown chicken on both sides, in batches if necessary, for 3-4 minutes per side.
Remove chicken and set aside. To the pan add the remainder of the ingredients (except sesame seeds and cauliflower rice). Increase heat and bring the mixture to a boil, scraping up any browned bits on the bottom of the skillet. Once the sauce has boiled and thickened up, add back the chicken and cook through until hot, about 1 more minute.
You can also use boneless, skinless chicken thighs here!
If you don't have rice wine vinegar on hand, you can substitute apple cider vinegar.
So many of you are already making this, but have been asking: What can you substitute for fish sauce? It is optional. Fish sauce is just an extra flavor booster that enhances the overall depth of the dish. But if you don't have it and don't want to buy it, skip it! The dish will still be lovely!