Cut the washed meat into slices, season with salt and pepper. Place a slice of bacon on each slice, add peeled, chopped onion and parsley. Roll the meat into rolls and secure with pins or toothpicks.
Fry the rolls in a casserole with melted butter and oil, cover with hot water and simmer until tender. During stewing, baste the meat with hot water as needed.
Dissolve mustard and plain flour in sour cream, pour in the juice and simmer for a while.