Prepare the Beef Filling: Heat olive oil in a large skillet over medium-high heat. Brown the beef cubes on all sides, about 5-7 minutes. Remove beef and set aside.

Cook the Vegetables: In the same skillet, add onions, carrots, and celery. Cook until softened, about 5 minutes. Add garlic and cook for another minute until fragrant.

Make the Gravy: Sprinkle flour over the vegetables and stir to coat. Gradually add beef broth while stirring constantly to prevent lumps. Add Worcestershire sauce, thyme, salt, and pepper. Return the beef to the skillet and simmer until the gravy thickens, about 10 minutes. Stir in frozen peas and remove from heat.

Assemble the Pies: Preheat oven to 400°F (200°C). Roll out pastry and cut circles slightly larger than your ramekins or individual pie dishes. Spoon beef filling into each dish, leaving ½-inch space at the top. Cover with pastry, crimping edges to seal. Cut slits in the top for steam to escape. Brush with beaten egg.

Bake to Perfection: Bake for 20-25 minutes until the crust is golden brown and filling is bubbly. Let cool for 5 minutes before serving.