COOK IT.
Preheat Pit Boss Ultimate Griddle to medium heat.
Using a mandolin, shred the lettuce and thinly slice the tomato and onions (if using). Slice avocados with a knife and set aside.
Place barbacoa on the griddle and add a small amount of beef broth to reheat and keep the meat moist. Stir occasionally until warmed through.
Heat refried beans in a separate pan until warmed.
Slice rolls in half and place them cut-side down on the griddle to toast until golden brown. Remove and set aside.
Sprinkle a layer of Monterey Jack cheese directly onto the griddle. Place the bottom bun onto the melting cheese, then flip to create a crispy cheese crust.
Spread sour cream onto the bottom bun over the cheese crust, followed by a layer of refried beans.
Add a generous portion of the reheated barbacoa.
Top with sliced avocado, 2 thin slices of tomato per sandwich, shredded lettuce, and sliced onion (optional).
Finish with crumbled cotija cheese, table salsa, and a drizzle of chipotle sauce if desired.
Place the top bun on, gently press, and serve immediately.