Step 1: Caramelize the Onions

• Heat butter and olive oil in a skillet over medium-low heat.
• Add sliced onions and cook slowly, stirring occasionally, for 15-20 minutes until they turn deep golden brown.
• Stir in salt, black pepper, garlic powder, Worcestershire sauce, and thyme.
• Pour in ½ cup beef broth and continue cooking for another 5 minutes until the onions are soft and flavorful.
• Remove from heat and set aside.

Step 2: Cook the Beef

• In a separate pan, heat a little olive oil over medium-high heat.
• Sear the thinly sliced beef for 2-3 minutes per side until browned but still tender.
• Remove from heat and let it rest while preparing the roll-ups.

Step 3: Prepare the Crescent Dough

• Preheat your oven to 375°F (190°C).
• Roll out the crescent roll dough and separate it into 8 individual triangles.
• Place the crescents on a parchment-lined baking sheet.

Step 4: Assemble the Roll-Ups

• Sprinkle Gruyère and mozzarella cheese on each crescent roll.
• Add a few caramelized onions on top of the cheese.
• Place a slice of cooked beef over the onions.
• Roll up the dough starting from the wide end, wrapping it around the filling.
• Pinch the edges slightly to seal the roll-up.

Step 5: Brush with Egg Wash and Bake

• In a small bowl, whisk together 1 egg and 1 teaspoon water.
• Brush the egg wash over each roll-up to give them a golden, crispy finish.
• Sprinkle with dried parsley for added flavor.
• Bake in the preheated oven for 12-15 minutes, or until golden brown and cooked through.

Step 6: Serve and Enjoy

• Let the roll-ups cool slightly before serving.
• Serve with extra caramelized onions and a side of warm beef broth or au jus for dipping.
• Enjoy your French Onion Beef Roll-Ups warm for the best flavor!