This mash, bacon, leek, and cheese pie is a comforting and delicious dish that combines creamy mashed potatoes, crispy bacon, sautéed leeks, and melted cheese. The mashed potatoes form a golden crust on top, while the bacon adds a smoky and salty flavor. The leeks bring a subtle sweetness and the cheese adds a gooey and melty texture. This pie is perfect for a cozy dinner or a potluck gathering.