I'd like to suggest tofu in a blender with a bit of liquid (your choice) chicken broth, water and/or soy sauce, nut milk (keep in mind they do add flavor). The amounts vary depending on how thick and creamy you like it. Also keep in mind that the longer you blend the thinner its texture may get. Like if you get the right texture but want to add herbs too and it gets too thin just add a dollop of tofu at the end to thicken it up again. Be sure to do a taste check, and pour over warm not hot hot cauliflower.
Me personally I like to roast the cauliflower, wedge sliced, laid on a drizzle of olive oil in an aluminum lined shallow baking pan. then drizzle the slices on their top side with the olive oil and sprinkle with course salt and pepper. Cover the pan completely with foil and seal it around the edges. Pop it into a 475 degree oven, pre-heated of course, for 15min. or 20min. Test for crisp/tender doneness with small knife. When tender use spatula to flip wedges over and sprinkle with course salt and pepper and return to oven till browned and done to your liking. We never have left overs even folks who don't eat cauliflower liked it. Hope it works for you too. I understand your challenge as we have various allergies in our family. We've been buying condiment items at Farmers Markets to jazz up things in tortillas and veggies. WOW! Has that improved our eating pleasure.