Preheat your oven to 200°C (390°F). Prepare your workspace and gather all ingredients.

In a large skillet over medium-high heat, pour in a splash of vegetable oil. Add the minced beef and cook until browned, about 5-7 minutes.

Using the same skillet, add more oil if needed and toss in the chopped onion. Sauté until soft and translucent, about 3-4 minutes.

Stir in the minced garlic, cooking for additional 1-2 minutes until fragrant.

Sprinkle the flour into the skillet, stirring continuously for 1 minute. Gradually pour in the Guinness while scraping up bits stuck to the pan.

Return the browned minced beef to the skillet and add beef stock, tomato paste, and thyme. Stir well and simmer for 45 minutes.

Remove the filling from heat and transfer it to a greased pie dish, spreading it evenly.

Roll out the puff pastry to fit over the pie dish and lay it over the filling. Seal edges to prevent leakage.

Whisk an egg and brush over the pastry. Cut a small slit in the center for steam to escape.

Bake in the preheated oven for 30 minutes or until the pastry is golden brown and crispy.

Once baked, allow it to cool for about 10 minutes before serving.