On a greased baking sheet, place the thawed bread loaves, cover and let rise in a warm place until doubled in size, about an hour.
Once doubled, roll each loaf into a 14 x 12 inch rectangle (it may be difficult to roll all of the way if it has not had time to rise).
In a bowl combine the egg, oil, garlic powder, salt, and Italian seasoning. Brush over the bread dough to within a ½ inch of the edges.
Add the ground beef, Canadian bacon, onion, olives, and cheeses on top.
Roll the dough up, jelly-roll style, starting with a long edge. Seal the seams.