Heat a pan and melt the butter, add the onions plus 2 tablespoons of water. Slowly sauté until soft and lightly golden. Meanwhile, process the cooked cauliflower into a purée. Stir the puree into the cooked onion, add the crème fraiche, sea salt and pepper, nutmeg, allspice/cinnamon and lemon juice, taste to check the seasoning.
