Preheat oven to 400 degrees F.

Cut the pork into generous cubes. In a Dutch oven brown the meat in the clarified butter. Add the onions and season with salt, pepper, marjoram and paprika. Add the tomatoes and place in preheated oven for about 30 minutes. Remove from oven and add the bell peppers, mushrooms and meat stock. Put back into oven for another 20 minutes.

Prepare instant mashed potatoes as indicated on the package but using slightly less water. Place the potato mixture into an icing bag (or create your own from a plastic freezer bag by cutting out one of the corners). On a large round ovenproof serving platter create a ring with the mashed potatoes. Beat the egg yolk and brush it onto the potato ring. Place in oven for about 5 minutes to slightly brown the top of the potatoes. Fill the ring with goulash and serve.