To start we will sear the chuck roast. To a large skillet over medium high heat, drizzle a few tablespoons of neutral oil. Season both sides of the roast with cajun seasoning(or salt) and pepper. Once the oil is hot add the roast and sear undisturbed for 2 minutes. Check for a good crust we just want it golden brown. Flip and sear for another 2 minutes until both sides are seared. Transfer the seared roast the crockpot.
To the same pot add in 1/2 cup of beef broth and the sliced onions. Sauté the onions for 2-3 minutes stirring to get the bits of the roast that stuck to the pan, we want all of that yumminess! Once the onions are a bit soft, transfer the onion and all of the juices into the crockpot. Stir.
Sprinkle the onion soup mix and italian dressing packet on top of the roast. Pour in the rest of the beef broth and stir. Cook on low for 8-10 hours(my preferred method) or on high for 6ish hours. Stir occasionally if able. Once the beef is done it is time to eat! Set your broiler on high. To the ciabatta bread add a healthy serving of beef to the bottom piece of bread. Add a slice of provolone cheese on top of the beef. Broil on high for 2 minutes, don't walk away! Broil until the cheese is melted over the beef and the bread is warm and toasted. Once removed from the oven smear on some horseradish aioli to the top piece of toasted bread.
Serve with a cup of the au jus (broth from the crockpot). Aggressively dip each bite in the au jus and enjoy (with plenty of napkins!).
