Directions

• Step One

  Begin by building the sandwich. Take each bun and smear each of them with some steak sauce. On the bottom bun, pile on the cheddar, the short ribs, the leftover mac n cheese, the gruyere, and top it with the other half of the onion bun and butter the exterior of the sandwich.

• Step Two

  n a cast iron skillet, or a panini press, place your sandwich in and turn the heat to medium high. I recommend using a panini press because it heats from both sides which allows the cheese to melt evenly while toasting the bread at an appropriate speed.Let the sandwich cook for a few minutes until all the cheese has melted and the exterior of the bread is crisp and toasty.

• Step Three

  Remove from heat and let the sandwich sit for a minute so that the cheese will thicken up and act as glue to the sandwich.