Cut the fillet into slices and press flat, then pepper. Then roll it into the ham in slices and place in a baking dish.
Now peel the onion, chop it up and sweat it in a pan. Then add the sour cream, cream, mustard, balsamic vinegar and lemon juice. Bring to the boil briefly and season with salt, pepper and broth to taste. Then pour the whole thing over the filet rolls.
Cook in a preheated oven at 180 ° C for about 40 minutes.
Serve garnished with parsley.
This goes well with rice and a fresh salad or salad and fresh flutes (baguette). A light white wine is recommended as a drink.