Begin by peeling and chopping the large potatoes into evenly sized pieces. In a large pot, cover them with salted water and bring to a boil over medium-high heat. Cook for about 15–20 minutes, or until the potatoes are tender when pierced with a fork. Drain the potatoes well and set them aside, letting any excess moisture evaporate.

Return the drained potatoes to the pot and add in the butter, milk, shredded cheese, salt, and pepper. Using a potato masher or fork, blend until the mixture is creamy, ensuring not to over-mix for a fluffy texture. Allow the mashed potatoes to cool slightly before using them as the luscious filling for your Delicious Irish Potato Pie.

While the potato mixture cools, preheat your oven to 375°F (190°C). This temperature will ensure a beautifully golden crust as the pie bakes. Prepare your baking sheet or pie dish by lightly greasing it.

Roll out your prepared pie crust on a lightly floured surface until it's about 1/8-inch thick. Carefully fit the crust into your pie dish, gently pressing it into the corners. If you're using a store-bought crust, ensure it overlaps the edges slightly for a complete seal. Trim any excess crust for a neat finish.

Spoon the creamy mashed potato mixture into the pie crust, helping it distribute evenly with a spatula. Smooth the top to create a lovely surface.

If you’re using a second pie crust, lay it over the filling and gently seal the edges by crimping with a fork or your fingers. Brush the top crust with the beaten egg for an enticing golden hue.

Place the pie in the preheated oven and bake for 25–30 minutes, or until the crust turns a beautiful golden brown and the filling is bubbly.

Once baked, remove your Delicious Irish Potato Pie from the oven and let it cool for about 10 minutes before slicing. This cooling period helps the filling set, making it easier to serve.