Preheat your oven to 375°F (190°C). In a large mixing bowl, whisk together the all-purpose flour, baking powder, and salt until combined. Gradually mix in the buttermilk, stirring until a soft dough forms.

Flour a clean surface and turn out the biscuit dough, gently kneading it for a minute. Roll it out to about ½-inch thickness and cut into rectangles. On each rectangle, place a generous slice of roast beef and a piece of provolone cheese.

Line a baking sheet with parchment paper. Place your filled biscuits on the sheet, ensuring they aren’t touching. Melt butter and brush the tops of the biscuits.

Transfer the baking sheet to your preheated oven and bake for 25-30 minutes until puffed and golden.

Let the biscuits cool for a few minutes. Serve warm with a side of au jus for dipping.