01 - Preheat oven to 400°F.
02 - Heat olive oil in a large Dutch oven or heavy pot over medium-high heat. Brown beef cubes in batches, ensuring proper searing on all sides. Remove browned beef and set aside.
03 - In the same pot, add onion, carrots, and celery. Sauté for 5 minutes until vegetables begin to soften and develop color.
04 - Add garlic and cook for 1 minute until fragrant. Stir in tomato paste and flour, cooking for another minute to remove raw flour taste and develop flavor.
05 - Return beef to the pot. Add red wine, scraping up any browned bits from the bottom of the pot. Stir in beef broth, Worcestershire sauce, thyme, rosemary, bay leaf, salt, and pepper. Bring to a simmer, cover, and cook on low heat for 1 to 1½ hours until beef is tender and sauce has thickened appropriately.
06 - Stir in frozen peas and discard bay leaf. Taste filling and adjust seasoning with salt and pepper as needed.
07 - Transfer filling to a 9-inch pie dish or baking dish, ensuring even distribution.
08 - Roll out puff pastry to fit over the dish. Lay pastry on top, trim excess dough, and crimp edges to seal. Cut a few slits in the top to vent steam during baking.
09 - Brush pastry surface evenly with beaten egg to achieve golden brown color.
10 - Bake for 25–30 minutes until pastry is puffed and golden brown. Let cool for 10 minutes before serving to allow filling to set.