Step 1

In a small mixing bowl, whisk together the mayonnaise and barbecue sauce until combined. Set aside.

Step 2

Heat olive oil in a skillet over medium low to medium heat. Add the slices of meatloaf and cook for about 3 to 5 minutes on each side until it's slightly golden brown on the outside and heated through.

Step 3

Fold over each slice of cheese so it's thick. Place a slice of cheese on top of each slice of meatloaf. Add 1 tablespoon of water to the skillet and cover with a lid for about 30 seconds to a minute just to warm/melt the cheese. Set the slices of meatloaf aside on a plate while you prepare the toast.

Step 4

Toast bread to desired doneness and spread the barbecue mayo over one side of all four bread slices.

Step 5

To assemble each sandwich, top one of the slices of bread with meatloaf, then layer on red onion and drizzle with mustard. Top with the remaining slice of bread (with the barbecue mayo on the inside) to form the sandwich. Serve and enjoy!