Clean and wash broccoli and cut into florets. Blanch in boiling salted water for about 5 minutes. Clean, wash and slice the mushrooms. Wash and clean the tomatoes and cut them into large pieces.
Drain broccoli, rinse with cold water and drain. Press the sausage meat as small dumplings out of the skin and fry it all around in hot oil. Remove and put aside. Fry the mushrooms briefly in the frying fat.
Grate the cheese roughly. Bring milk to the boil, stir in 2/3 of the cheese and let it melt. Stir in sauce thickener and bring to the boil again. Season sauce with salt and pepper. Put the vegetables and roast dumplings in an ovenproof dish.
Pour sauce over it and sprinkle the rest of the cheese over it. Bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for approx. 25 minutes. Garnish with parsley leaves.