Clean the cauliflower, cut into florets and wash. Put the drained cauliflower florets in a large greased casserole dish. Bring 80 g butter and 1/4 litre milk to the boil. Stir the remaining milk and flour until smooth.
Take hot milk from the stove and stir in the flour. Place back on the hot plate and simmer for 2-3 minutes while stirring. Separate 4 eggs. Remove the sauce from the heat and stir the egg yolks into the hot sauce.
Season the sauce with salt, pepper and nutmeg. Beat the egg whites until stiff and carefully fold into the sauce. Spread over the cauliflower and sprinkle with cheese. Bake in the preheated oven, 2nd shelf from below (electric oven: 175 °C/ gas: level 3) for approx. 50 minutes.
In the meantime, soak rolls in cold water for the meatballs. Peel onions and dice one finely. Cut the remaining onions into rings. Wash parsley, dab dry and chop, except for something to garnish.
Squeeze out the bread roll well and knead it together with the minced meat, remaining egg, diced onion, some salt, pepper and mustard. Add chopped parsley, except for something to sprinkle on the bread. Form about 20 small meatballs with moistened hands.
Heat the oil in a pan and fry the balls for about 8 minutes, turning them over. Remove the meatballs, clean the pan and melt the remaining butter in the pan. Brown the onion rings in it.
Serve meatballs with the onion butter with the cauliflower casserole. Cranberries from the glass taste great with it.