Heat a tablespoon of oil in a large pot over medium-high heat. Add the diced tender beef and brown it for 5–7 minutes until a rich, caramelized crust forms.

Once browned, add the chopped onions and diced carrots, cooking for an additional 5 minutes until they soften.

Pour in the cup of Guinness beer and the two cups of beef stock, stirring well to integrate all ingredients. Season generously with salt, pepper, and your choice of fresh herbs like rosemary or parsley.

Bring the mixture to a simmer, cover the pot, and let it cook for 1.5 hours, stirring occasionally.

After the simmering time, assess the gravy's consistency; if it is too thin, simmer uncovered for an extra 5 minutes.

Preheat your oven to 400°F (200°C). Roll out the chilled puff pastry on a floured surface and line a pie dish with half of it.

Carefully fill the lined dish with the savory beef mixture, ensuring it's evenly spread out. Cover with the second layer of puff pastry, sealing the edges together, and cut slits in the top to allow steam to escape during baking.

Place the assembled pie in the preheated oven and bake for 30–40 minutes, or until the crust is golden brown and puffed.

Once baked, remove the pie from the oven and let it cool for 10 minutes before slicing.

Serve warm, perhaps with creamy mashed potatoes or sautéed greens on the side for a complete meal.