Preparation

• Preheat the oven to 350°F. Spray a 9×13-inch baking dish with nonstick cooking spray and set aside.
• In a large skillet over medium heat, melt 4 tablespoons salted butter. Add 3 cups small-diced onion, 2 teaspoons granulated sugar and ½ teaspoon black pepper to the skillet and stir to combine. Continue cooking until the onions turn a golden brown color. Remove from heat and place on a separate plate until ready to assemble.
• Unroll one of the 2 tubes crescent dough sheets and press it into the prepared baking dish, ensuring it goes up the sides about 1 inch.
• Lay half of the 8 ounces sliced provolone cheese on top of the dough.
• Layer 14 ounces deli sliced roast beef on top of the cheese.
• Spread the cooked onions on top of the roast beef.
• Place the remaining provolone cheese on top.
• Unroll the second crescent dough sheet and place it on top. Pinch the two doughs together along the seams and tuck the excess dough under the bottom.
• Whisk together 1 large egg, 1 ½ tablespoons dried onion soup mix, 1 teaspoon dried parsley flakes, and ½ teaspoon dried thyme in a medium-sized bowl.
• Brush the egg mixture all over the top of the dough, using it all.
• Cover with nonstick foil and bake for 30 minutes. Remove the foil and bake an additional 15-20 minutes until deep golden brown on top.
• Let cool for 10 minutes.
• While the squares are cooling, make the 1 ounce packet au jus gravy mix per the package directions using the 3 cups cold water.
• Cut into squares and serve with au jus for dipping.