Preheat your oven to 375°F (190°C) and line a baking dish with parchment paper.
Lay tortillas flat, add roast beef and cheese, then roll tightly.
Mix melted butter, garlic powder, and onion powder. Brush over each roll up.
Arrange rolls seam-side down and bake for 18–22 minutes or until golden brown.
In a small saucepan, whisk au jus mix with water and simmer until rich and fragrant.
Slice rolls, garnish with parsley, and serve warm with au jus for dipping.
