Click link up above for the Slow-Roasted Roast Beef with Mustard, Garlic, and Thyme recipe.
Prepare the au jus per package instructions. Side Note: If you have the time to make your own au jus - click link up above for instructions.
Preheat your oven to broiler. Place the opened slider buns on a baking sheet. Place into the oven and cook, making sure to watch carefully, for a few minutes or until the buns start to get golden. Remove from the oven.
Place the thinly sliced roast beef slices into the HOT au jus for a few seconds to warm up then place on the bottom buns. Add tomato slice on top of the meat then season with sea salt and freshly cracked pepper, to taste, followed by some provolone cheese. Spread some cream horseradish sauce on the top buns, if desired. Place back under the broiler for a few minutes or until cheese is melted. Remove from the oven and serve with au jus. Enjoy!