Step 1

Spray the crock of a 4 to 6-quart slow cooker with nonstick cooking spray. Add the chuck roast. In a small bowl, whisk together the au jus mix, gravy mix, and 1 cup of water. Pour it over the roast. Cover and cook on low for 8 to 10 hours.

Step 2

Once the beef is super tender, carefully remove the roast from the slow cooker and shred the meat when cool enough to handle. Discard the fat and return the shredded meat to the gravy in the slow cooker. Mix to combine.

Step 3

Preheat the oven to 400°F. Warm the bread in the oven for 3 to 5 minutes to crisp up the exterior.

Step 4

Dress the bread with mayo and Creole and/or yellow mustard. Add generous amounts of the shredded beef and gravy to the sandwich. Top with the shredded cabbage and pickles.