Dice the buns. Warm the milk and pour it over the buns. Leave to soak for approx. 1 hour
Clean and wash the leek and mushrooms. Halve the mushrooms. Cut leek into rings. Grate cheese finely. Peel onions, wash parsley. Chop both
Fry the onions in 1 tbsp. hot butter. Steam parsley, except for a little bit. Knead both with bread roll, eggs, 1 tsp salt and pepper. Form 12-16 dumplings. Cook in boiling salted water in a wide pot for about 20 minutes
Fry the mushrooms in hot oil. Steam the leek briefly and season. Stir in 3/8 l water, cream and stock. Bring to the boil, cover and simmer at low heat for about 5 minutes
Melt the cheese in the sauce, season to taste. Stir in the sauce thickener, bring to the boil. Drain dumplings. Arrange everything and sprinkle with the rest of the parsley. If necessary, froth up 1 tbsp. butter in a pan, drizzle over it