Cut the dumplings into strips and place in a baking dish. Cut the ham into cubes or pieces and distribute on the Maultaschen. Cut the onions into small pieces.
Heat 1 tablespoon of margarine in a separate saucepan. When it has melted add the onions. When the onions are fried golden brown, add 3 teaspoons of flour and stir well. Deglaze with cream. Season to taste with salt, pepper, garlic powder and (importantly) vegetable stock powder.
Pour the sauce over the dumplings and the ham and finally spread the grated cheese over them. Bake in the oven at 180 ° C until the cheese has melted and is slightly brown.