There are few dishes as cozy and comforting as traditional Shepherd’s pie! My favorite part of this recipe is the savory gravy, which works beautifully with the fluffy mashed potatoes piled on top. If you can, use an English or Irish cheddar for the potatoes!
1 tablespoon olive oil
1 pound (450g) ground beef or ground lamb
1 medium onion, chopped
2 medium carrots, 1 cup chopped
1 tablespoon flour
1 ½ teaspoons garlic powder
2 teaspoons dried thyme
2 tablespoons tomato paste
1 ½ cups (355ml) beef stock, chicken stock, or veggie broth
1 tablespoon plus 1 teaspoon Worcestershire sauce
1 cup (160g) frozen peas
2 pounds (907g) potatoes
8 tablespoons (113g) butter
2/3 cup (160ml) milk
1 cup (113g) grated sharp cheddar cheese
3/4 teaspoon fine sea salt, plus more to taste
Preheat the oven to 350°F (180°C). Use convection if your oven has it. Set aside a 9×9-inch baking dish, or make this in a 10-inch cast iron skillet, which is used on the stovetop and for baking the Shepherd’s pie later in the recipe.
Make mashed potatoes: Peel the potatoes and cut them into pieces roughly the size of golf balls. Heavily salt a large pot of water, add the potatoes, and bring to a boil. Cook until tender, 15 to 20 minutes.
Meanwhile, heat the butter and milk in a small saucepot and keep warm.
Strain the potatoes, then use a food mill or potato ricer to get them back into the pot (or add them and then mash them with a potato masher).
Pour the hot milk into the potatoes and mix. Add the cheese and mix to combine. Season to taste with salt. I start with 1/4 teaspoon and go from there. Keep the potatoes warm while you make the filling.
Brown the meat: In a 10-inch cast iron skillet, heat the olive oil over medium heat. Add the ground beef (or lamb) and brown, breaking it into crumbles. Transfer to a bowl and place the skillet back over the heat.
Make the gravy: Add the onion and carrots and cook, occasionally stirring, for 5 minutes. Sprinkle in the flour, then stir until smooth.
Add garlic powder, dried thyme, and tomato paste, and cook, stirring around the pan for 30 seconds.
Pour in the broth and Worcestershire sauce, then add the browned meat with all the juices back to the skillet. Bring to a simmer and cook until it forms a nice gravy, 3 to 5 minutes.
Turn off the heat and stir in the peas. Then, season to taste with salt (1/4 teaspoon to 1/2 teaspoon) and a generous pinch of pepper.
Bake: If using a baking dish, transfer the meat and gravy to it. Or, if your skillet is oven-safe and at least 10 inches wide, you can assemble the Shepherd’s pie in it.
Spread the warm mashed potatoes over the filling, spreading evenly and making sure it covers all the way to the edges. Then, bake on a sheet pan for 25 minutes, turning halfway (the sheet pan catches any drips over the sides). Let rest 5 to 10 minutes before serving.