2 tablespoons butter
Preheat oven to 350F. Grease the casserole dish with the 2 tablespoons of butter.
2 Russet Potatoes (peeled and sliced 1/8-inch thick on mandolin)
Salt and freshly Ground Pepper
For the Potato Layer: Arrange the thinly sliced potatoes on the bottom of the casserole and season with salt and pepper.
2 tablespoons Olive Oil
1/2 Yellow Onion (chopped)
For the Meat Layer: Heat the olive oil in a large skillet over medium-high heat. Add the onion, and cook until softened, about 3 to 4 minutes.
1 clove Garlic (sliced thinly)
Add the garlic, and cook until fragrant, about a minute.
1 pound ground Lamb
Salt and Pepper
Add the ground lamb, and cook, breaking up, until browned, about ten minutes. Season with salt and pepper. Pour over the sliced potatoes in the casserole pan.
2 1/2 tablespoons Butter
For the Cheese Sauce: Heat the butter in a saucepot over medium heat.
3 tablespoons All-Purpose Flour
1/4 cup Stout Beer
Add the flour and and beer and whisk together.
2 cups Milk
Add milk and keep whisking until all is integrated.
1/2 cup Cheddar Cheese (grated)
Add the cheese to the beer mixture and keep whisking until sauce is smooth. Pour over the ground lamb layer in the casserole.
1 Sheet Puff Pastry (cut to fit a 9x13 casserole)
For the Pastry: Cut the puff pastry to fit the 9x13-inch casserole.
Dock the puff pastry by piercing with holes all over.
Bake on a greased sheetpan until golden brown, about 10 minutes. Place on top of cheddar and beer sauce layer.
2 tablespoons Unsalted Butter
For the Peas and Carrots: Heat butter in large skillet over medium heat.
2 cups frozen Peas
2 Carrots (chopped)
Add the carrots, season with salt and pepper, and saute until softened, about 5 minutes. Add the peas, cook another 5 minutes. Pour over the puff pastry.
1 pound Russet Potatoes
For the Mashed Potatoes: Combine peeled, cubed potatoes with 6 quarts of water in a stockpot and bring to a boil. Cook until potatoes are tender, about 20 to 25 minutes.
1/2 cup Heavy Cream
4 tablespoons Butter (cut into tablespoon-size pieces)
Drain water, add the butter and cream, and mash with a potato masher to desired consistency. Spread over the carrots and peas in the casserole.
2 cups Cheddar Cheese (grated)
For the Cheese: Sprinkle the cheese in an even layer over the mashed potatoes. Bake casserole until cheese has melted, about 20 minutes. Remove from the oven and set aside.
1 Onion (sliced paper-thin on a Mandolin)
1 cup Olive or Vegetable Oil
For the Fried Onions: Meanwhile, in a medium skillet, bring the oil to medium heat. Add the onions, fry until crisp. Transfer to papertowel lined plate.
Top the casserole with the fried onions.