Firstly prepare the cauliflower by washing it and cutting it into individual little florets, with all the hard woody stems discarded. Place the florets in a double boiler and steam until they are soft and yielding when pierced with a sharp knife. Remove the cauliflower florets from the heat and place in a buttered, ovenproof serving dish.
In a large mixing bowl mix together the creme fraiche, mustard, nutmeg, double cream, a generous grating of black pepper, and half the grated cheddar cheese.
Pre-heat the grill to its hottest setting.
Pour the creamy sauce over the hot cauliflower, sprinkle with the remaining cheese and brown under the hot grill, for about 10 minutes, until the top is golden brown and crisp.
Serve with freshly chopped parsley sprinkled on top.