01 - Preheat oven to 375°F (190°C). Lightly coat a 9x13 inch baking dish with non-stick cooking spray.
02 - Unroll one can of crescent roll dough and press it evenly into the bottom of the prepared baking dish, pinching seams to seal.
03 - Distribute the sliced roast beef evenly over the dough base, then sprinkle with grated Swiss cheese.
04 - In a small bowl, combine dry onion soup mix, melted butter, Worcestershire sauce, and garlic powder. Drizzle this mixture evenly over the cheese layer.
05 - Unroll the second can of crescent roll dough and lay it over the filling, pinching seams together to form a uniform top layer.
06 - Place the dish in the oven and bake for 15 to 20 minutes, or until the top is golden brown and baked through.
07 - Meanwhile, warm beef broth in a small saucepan over medium heat for use as a dipping sauce.
08 - Allow to cool slightly after baking, then cut into equal squares.
09 - Serve the squares warm with the heated beef broth on the side for dipping.