Heat a large pot over medium-high heat and add a splash of oil. Brown the beef for about 5–7 minutes, stirring frequently.

Mix in chopped onions and diced carrots, cooking for another 5 minutes until softened.

Pour in Guinness beer and beef stock, stirring to deglaze. Season with salt, pepper, and herbs, then simmer covered for about 1.5 hours.

If gravy is thin, remove the lid and cook uncovered for an additional 5 minutes to thicken.

Preheat oven to 400°F (200°C). Roll out puff pastry and line a pie dish. Fill with the beef mixture and cover with pastry. Seal edges and cut slits for ventilation.

Bake for 30–40 minutes until the crust is golden brown. Remove and let cool for 10 minutes before serving.