Lightly salt and pepper the pork steaks or medallions, fry in hot fat for 3-4 minutes (medallions a little shorter) on only one (!) Side. Place with the fried side down in a well-greased baking dish. Brush the un-fried side with mustard.
Finely dice the bacon and onions and sauté in the frying fat. Then mix well with cheese, egg yolk, cream, salt and pepper. Distribute the mixture evenly on the pieces of meat and put a few flakes of butter on top. Baked golden brown in a preheated oven at approx. 200 degrees.
Serve with fried potatoes made from raw potatoes and a green salad.