In a small bowl whisk together rice wine vinegar, cornstarch or arrowroot starch and soy sauce. Set aside.
Remove leaves and cut cauliflower into small to medium florets. Heat olive oil in a wok or large skillet over medium-high. Add cauliflower and cook tossing occasionally, until some of the pieces have browned edges and the cauliflower is soft, about 7–9 minutes.*
Add the soy sauce mixture to the cauliflower and coat completely. Stir together on low heat. You will start to see the sauce thicken.
Continue cooking and add sesame oil, garlic, fresh ginger and cashews. Continue stirring so that the cauliflower is well covered for about 3-4 more minutes.
Remove from heat, add to bowl and top with scallions, sesame seeds. Enjoy!
* I put a cover on the pan for some of the time to ensure the cauliflower would soften in the inside.