1. Heat olive oil in a large pot over medium-high heat. Season beef with salt and pepper, then brown in batches until all sides are seared. Set aside.

2. In the same pot, reduce heat to medium and cook the diced onion until soft. Add minced garlic and cook for another minute.

3. Add mushrooms and cook until their moisture evaporates and they start to brown.

4. Stir in tomato paste and flour until vegetables are coated. Slowly pour in beef broth while stirring to avoid lumps. Add Worcestershire sauce and bring to a simmer.

5. Return the beef to the pot. Cover and simmer on low heat for 1 to 1.5 hours until the beef is tender and sauce is thickened. Let it cool slightly.

6. Preheat oven to 400°F. Pour filling into a pie dish. Lay puff pastry over the top, trim and crimp edges, and cut slits for steam to escape.

7. Brush the pastry with beaten egg yolk. Bake for 25–30 minutes until puffed and golden brown. Let rest for 10 minutes before serving.