Sear the chuck roast in a large skillet with a bit of oil over medium to medium - high heat. This will take 4-5 minutes per side.
Place the seared roast in the crock pot. Deglaze the skillet with ½ cup of stock. Stir to remove any bits from the pan. Pour over the roast.
Add onions, the remaining stock, Worcestershire sauce, soy sauce, and seasoning. Place the lid on the crock pot and cook on low for 6-8 hours until the roast is fall-apart tender.
4 cups beef stock, 1 onion , 2 tablespoons Worcestershire sauce, 2 tablespoons soy sauce, ½ teaspoon garlic powder, ½ teaspoon onion powder, ½ teaspoon pepper
Remove roast from the crock pot and place on a large plate.
Break the roast into large chunks of meat, removing any fat or connective tissue.
Skim off any grease from the top of the liquid remaining in the crock pot. This is the au jus for dipping.
Cut rolls in half lengthwise and place on a baking sheet. Toast buns in a preheated 400°F oven for 3-5 minutes.
4 crusty sandwich rolls
Grab a generous amount of meat with a pair of tongs and dip it into the liquid in the crock pot. Allow most of the liquid to drip off the meat. If it's too wet, it will make your bun soggy. Place the meat on the bun.
4 slices Provolone cheese
Top with a slice of cheese.Place in oven for 3-5 minutes until the cheese is melted.
Serve hot with a small bowl of the au jus on the side for dipping.
Notes
This makes 4-6 sandwiches piled with a generous amount of meat. Adjust the amount of meat for each sandwich to your liking.
Sear your chuck roast well on all sides. This helps develop flavor.
Allow the skillet to cool slightly before deglazing the pan. All the brown bits from the roast have a ton of flavor, and you don't want them to go to waste. Add a bit of the stock to the still very warm skillet and scrape up any bits from the pan. Pour the deglazing liquid over the roast in the crock pot.
Toasting the buns helps prevent them from turning soggy once the meat is added.
The onions are added for flavor. They can be served on the sandwich layered with the shredded beef or discarded.
Aus JusThe liquid from the crock pot is your au jus, which can be used for dipping the sandwiches into.
Skim off the top layer of grease from the au jus.
Taste the au jus. If salt is needed, add a bit to your liking. This will vary depending on the type of soy sauce and the stock used.
If the au jus seems to be lacking in flavor, place it in a small saucepan over medium heat to reduce and intensify the flavors. Once it comes to a simmer, allow it to reduce until the flavor is to your liking. My au jus was perfect right out of the crock pot, but this will vary depending on your ingredients and how well you seared your roast.