Season the chuck roast on all sides with salt, pepper, and garlic.
Melt butter in a skillet over medium high heat and sear chuck roast on all sides.
Put the seared chuck roast in a crock pot.
Add sliced onions, minced garlic, Worcestershire sauce, beef broth, beer, and Au Jus packet to the hot skillet, stir, and let simmer.
Pour the onion and gravy mixture over chuck roast in the crock pot and let cook on low for 6-8 hours.
Shred the meat and discard any extra fat.
Strain the Au Jus for serving.
Slice and toast the bread, then build sandwiches with the meat and provolone cheese.
Put in the air fryer for a few minutes to melt the cheese.
