Also, yes, definitely add some potato! I add them to any soup that I wanted "creamed", in fact, potato and nutritional yeast on its own should make it nice and "cheezy".
I make a dairy free cauliflour soup for my sister, I'll post the recipe here so you can get some inspiration to adapt it to your recipe. She is transitioning to a vegetarian diet.
“Creamed” Cauliflower-Potato Soup
If you follow MWL, this recipe will work just fine without the cashew “cream”. Do not be too fussy about the cuts of the vegetables since it gets pureed anyways.
2 onions, diced.
3 cloves garlic, minced.
1 cup water, or enough to cover the onions.
1 banana pepper, minced (optional).
2 ribs celery, sliced.
4 cups peeled and diced potatoes.
4 cups peeled and diced cauliflower.
1 tbsp dried thyme.
Cayenne pepper, to taste.
4 cups vegetable stock.
½ cup raw cashews blended with 1 cup water and 2 tsp nutritional yeast.
Salt, and pepper, to taste.
Place the onions, garlic, pepper, celery, and water in a pot. Bring to a boil and cover. Bring the heat to low to steam the vegetables. Steam for about 10 minutes. Add the potatoes, cauliflower, thyme, cayenne pepper, and stock. Bring to a boil and cook for about 20-30 minutes (until potatoes are cooked). When cool enough, puree in a blender, in batches if you need to. Return to the pot and add the cashew cream. Mix thoroughly. Season with salt and pepper, to taste.
There's celery in it because she loves celery. I'm not sure, but I think she's hiding a culinary genius side!