Boil the rice. Dice the meat loaf. Cut the mushrooms into leaves. Finely chop the onion and parsley. Steam everything together in the hot fat for a few minutes. Season with the sprinkling of the seasoning and add the juice of half a lemon and the cream. Cook everything well and mix with the rice and 40 g grated Gruyère. Pour into a buttered casserole dish. Scatter the rest of the Gruyère on top and sprinkle with flakes of butter. Bake in a well preheated oven for about 20 minutes.