Ahh yes so many ways to do meatloaf. Smoked meatloaf is amazing, won't eat it any other way. But sometimes I make the meat mixture with green peppers and onions in it. Seasoning of some kind too. Depends on my mood. Sometimes I put salsa in it too. You can roll the meat mixture out flat, line it with ham, sliced peppers and provolone cheese, then roll it back up into your loaf. Or I put the thick mozzarella chunks in the middle. If you use cheese though, you just gotta make sure the edges are sealed, otherwise it leaks.
