Separate the thin slices of beef into individual pieces. Scale into 8 oz. portions. Place side-by-side in a storage container in a single layer. Cover and refrigerate until needed.
Heat a 5 lb. bag of Italian au jus gravy and 3 Tbsp. of paprika to 160°F. Whisk until blended. Hold at 120°F. Dunk the beef in the gravy for
Place the tobacco onions in a heated 350°F deep-fryer. Cook until caramelized, resembling pieces of shredded tobacco. Allow to drain.
Place in a storage container. Cover until needed.
TO PREPARE À LA CARTE PORTION:
Open the bun, leaving it hinged at the bottom. Spray the inside of the bun with cooking spray. Place, oiled-side down, on a heated flat griddle. Grill until golden brown.
Place 8 oz. of beef in the gravy just long enough to warm and make it wet, about 15–30 seconds. Stack the beef down the center of the bun. Ladle 1½ oz. of gravy over the top of the warmed beef.
Drizzle 1½ oz. of BBQ sauce on top of the beef. Shingle 4 Muenster triangles on top of the beef and sauce. Place under a heated salamander to melt the cheese. Spoon 2 oz. of green goddess slaw on top of the cheese. Stack 1 oz. of tobacco onions down the center of the slaw. Place on a warmed serving plate.