If using a roast, salt and pepper on both sides and brown. Add water to cover and braise on stove top until well cooked; set aside and cool. When cool, shred the beef and remove all fat.
If using ground beef, brown it in a large skillet, breaking it up very fine. Pour off fat and allow the beef to cool.
In a large skillet, saute the onions and garlic in 4 Tbsp. butter until onion is almost golden brown. Add the shredded cabbage and cook until limp. Add salt, pepper, cayenne, and shredded beef (or browned ground beef) to the cabbage mixture and let stand until cool.
Put the bread loaves into 4 sections each and let rise. Roll out each section into an 8-inch square. Place 2 to 3 Tbsp. of filling onto the square and roll up, folding the sides in to form a tight seal. Set the Bierocks aside to rise again.
Place the bierocks on a baking sheet that has been sprayed with cooking oil and bake in a preheated 350-degree oven for 25-30 minutes until golden brown. If you like crusty bierocks, spray the rolls with water just as they begin to brown. This may be repeated during the browning process. Serve hot.