Spread a thin layer of mustard on each steak and divide the pickles, ham and onion among the steaks. Fold in the sides and roll as for stuffed cabbage. Secure with a toothpick, if necessary.
Heat oil in large Dutch oven and brown beef rolls on all sides. Remove meat and add flour to the pan, and cook to a light brown to make a roux. Stir in the stock, wine, tomato paste, and salt and pepper. Bring to a boil and simmer 1 minute.
Return beef rolls to the pan and spoon over some of the sauce. Cover and cook over low 45 minutes to 1 hour, adding more liquid as necessary during cooking.
When the rolls are cooked, transfer to a serving dish and remove the toothpicks, if used, and ladle over the sauce. Dollop with sour cream and chopped parsley. Great with rice, mashed potatoes, Finger Dumplings or Drop Potato Dumplings.