Heat pie irons for 1 to 2 minutes in fire. While pie irons are heating butter 1 side of each slice of bread.
Place a small amount of butter in the pie iron with the roast beef and onion. Cook 1-2 minutes turning half way through.
Open pie iron and place 1 slice of bread on top of beef and onions with the butter side up.
Close the pie iron and flip over. Then open and place 2 slices of provolone cheese and the second slice of bread on top again with the buttered side up.
Close pie iron and cook for 2-3 minutes turning several times. Check and cook until golden brown.
