Add the riced cauliflower, salt, pepper, heavy cream, and butter to a large sauce pan and bring to a simmer over medium-high heat. The mixture will be fairly thick.
Cook, stirring often, until the cauliflower is tender and mixture is creamy, about 10 minutes.
Use immersion blender to blitz mixture a little finer. Remove from the heat and stir in the cheese.
Serve the grits topped with extra cheese if desired.
