Get butcher to pound the meat thin, or you can have the butcher slice it thin on an electric slicer.
If you are getting your meat from a store that does not have a butcher to pound the meat slices thin, then place a slice between 2 pieces of waxed paper and pound it yourself with either a heavy skillet or a mallet.
Combine filling ingredients (except mozzarella or fontina and bread) and the prosciutto di Parma and mix together very thoroughly with a spoon or your hands.
After the ingredients are mixed together, add the pieces of bread and mix again, lightly.
Cut each slice in half to make 4 pieces and top with 2 slices of mozzarella or fontina cheese and 2 slices of the prosciutto di Parma per braciole. Then spread ingredients on top.
Fold in the sides and roll them up longways very tightly, as you would an egg roll, securing the rolls with string or wooden toothpicks.
Each roll will be about 5 inches long and about 1 1/2 inches thick.
Pour olive oil into a large and very hot skillet.
Brown beef rolls on all sides in the hot olive oil.
Transfer the rolls to a pot and cover with the marinara sauce and then cover with lid and simmer for 30 minutes. I suggest my marinara sauce, recipe #84217.
To serve, slice the bracioles crosswise diagonally and also in slightly larger pieces crosswise. You can also serve the bracioles without slicing them. Serve 1 braciole per person.