Bierock is often served with mustard as a dipping sauce, whether they contain cheese or not. It is traditionally made with beef, but other ground meats can also be used. In a bierock, shredded cabbage is also commonly substituted for sauerkraut.
Combine 4 cups of flour, yeast, sugar, and salt in a large bowl. Mix well and set aside.
Melt butter in a saucepan with water and milk. Remove from heat and let cool to 120°-130°. Stir in the flour mixture and eggs.
Blend at low speed until moistened, then beat for 3 minutes at medium speed. Then, gradually add the remaining flour by hand until the dough is firm.
Knead for about 10 minutes on a floured surface. Transfer to a greased bowl and turn to grease the top. Let it rise in a warm place for about an hour until it doubles in size. Then punch dough down and let it rise a second time.
To make the filling, brown beef with onion, salt, and pepper; drain. Add cabbage and mix well. Make four equal portions of dough. Roll out each piece to 15×10 inches. Make rectangles. Trim to 5 inches square. Fill each rectangle with 1/3 to 1/2 cup filling.
Pinch the four corners together to seal the filling. Continue with remaining dough and filling.
Grease baking sheets and place them. Bake at 375 degrees for 30 minutes or until brown.