Initiate by preheating the oven to a temperature of 400ºF. Meanwhile, line a baking tray with high-quality parchment paper for optimal baking conditions.

Proceed by delicately separating each biscuit into two distinct layers. On each layer, apply a measured amount of the horseradish sauce. On half of these biscuit layers, position a slice of the provolone cheese followed by the roast beef. Subsequently, cover the meat and cheese preparation with the remaining biscuit layers. Ensure that the edges are meticulously pinched to encapsulate the filling. Place these assembled biscuits on the previously prepared baking tray.

Transfer the baking tray to the preheated oven and allow the biscuits to bake for a duration ranging from 12 to 15 minutes. The optimal indication of readiness is a golden-brown appearance on the surface of the biscuits.

In the interim, while the biscuits are undergoing the baking process, prepare the Au Jus Gravy. Ensure strict adherence to the directions provided on the packaging of the mix for optimal results.