Cut the sausages into slices and fry them briefly in an ovenproof pan. Add the butter vegetables and steam with the lid on a little over medium heat until the herb butter has melted. Dust with the flour and roast again while stirring. Stir in the cream or milk and season to taste, then stir in the grated cheese as well.
Now distribute the dumpling evenly on top and bake the casserole at 180 degrees hot air for about 30 minutes. Finally, turn on the grill for 2 minutes to brown the layer of dumplings.