Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.
In a large mixing bowl, whisk together the flour, baking powder, salt, garlic powder, and onion powder.
Add the cold cubed butter to the flour mixture and use a pastry cutter or your fingers to blend until the mixture resembles coarse crumbs.
Stir in the shredded cheddar cheese.
Pour in the buttermilk and mix until just combined. Do not overmix.
Turn the dough out onto a floured surface and gently knead it a few times until it comes together. Roll it out to about 1-inch thick.
Cut the dough into rounds using a biscuit cutter or a glass and place them on the prepared baking sheet.
Bake in the preheated oven for 12-15 minutes, or until golden brown.
While the biscuits are baking, heat the beef broth, Worcestershire sauce, Dijon mustard, and black pepper in a saucepan over medium heat until warm.
Once the biscuits are done, slice them in half and layer the sliced roast beef inside. Serve with the warm broth for dipping.
Garnish with chopped parsley if desired.
