Preheat oven to 375°F (190°C). Lightly grease a baking sheet.
Flatten each biscuit slightly and place a slice of roast beef, a sprinkle of Swiss cheese, and a spoonful of caramelized onions in the center. Fold the dough over and pinch the edges to seal.
Mix melted butter with garlic powder and parsley, then brush over the biscuits.
Place biscuits on the baking sheet and bake for 12–15 minutes, or until golden brown.
In a small saucepan, heat beef broth and Worcestershire sauce over medium heat until warm.