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Shepherd's Pie, a savory ground lamb casserole dish.

Shepherd’s Pie, a savory ground lamb casserole with cheddar garlic mashed potatoes

This classic casserole dish is made with rich filling of ground lamb, chopped vegetables and a thick tomato-based sauce all topped with a cheesy mashed potato crust and baked in the oven. It’s easy comfort food at its best. I added a chopped mushrooms to up the deep meaty flavor of the filling, as well as a teaspoon of marmite, which is a trick that punches up the umami (savory flavor) of the dish. If you don’t have marmite and don’t feel like buying it for this dish, try substituting 1 teaspoon of soy sauce in place. It won’t add as much depth to the filling but it will boost the umami flavor. Finally you can substitute ground lamb with ground beef or another ground meat of your choice or make it vegetarian by increasing the mushrooms to 2 pounds or using a meatless ground crumble.
Course Main Course
Cuisine American, European
Keyword casserole, cottage pie, ground beef, ground lamb, main course, mashed potatoes, shepherd's pie
Prep Time 40 minutes
Cook Time 50 minutes
Rest Time 10 minutes
Total Time 1 hour 30 minutes
Servings 8
Calories 428 kcal
Author Irvin

Ingredients

Mashed Potato Topping

  • 2 pounds Yukon Gold Potatoes or another yellow potato
  • 6 large cloves garlic peeled
  • 1 cup grated white cheddar or regular medium yellow cheddar
  • 6 tablespoon unsalted butter melted
  • 1/2 teaspoon kosher salt
  • 1/2 teaspoon ground pepper
  • 1 tablespoon chopped flat-leaf parsley otherwise known as Italian parsley
  • 1/2 cup heavy cream

Filling

  • 1 3/4 pounds ground lamb see note above
  • 1 tablespoon olive oil
  • 3/4 pound cremini mushrooms quartered
  • 1 medium yellow onion chopped
  • 4 large carrots chopped
  • 4 large cloves garlic chopped
  • 1 1/2 cups chicken or vegetable stock
  • 2 tablespoons tomato paste
  • 2 1/2 tablespoons all-purpose flour
  • 1 1/2 teaspoon Marmite see headnote above
  • 1 teaspoon kosher salt
  • 3/4 teaspoon ground pepper
  • 1/2 teaspoon dried ground thyme
  • 1 cup corn kernels fresh, frozen or canned
  • 1 cup frozen peas

Instructions

  1. Make the mashed potato topping by peeling and chopping the potatoes into 1-inch cubes. Bring a large pot of salty water to a boil. Add the potatoes and garlic to the pot. Cook for 10 minutes or until a fork inserted into a potato cube enters easily. 

    Boil the cubed potatoes
  2. Drain the potatoes in a colander, and then return them to the still warm pot. This will help dry them out. Mash the potatoes with a potato masher or fork. Add the melted butter and mix until incorporated. Add the cheese and repeat. Mix in the salt and pepper, then add the parsley and cream. Mix and adjust seasoning to taste. Preheat the oven to 400°F.

    Mash the potatoes with the cheese and other potato ingredients.
  3.  Make the filling by placing the ground lamb in a large saute pan. Brown the meat, stirring frequently, until cooked fully, about 10 minutes on medium heat. Pour the meat and any pan juices into a heatproof bowl.

    Brown the ground lamb
  4. Do not wipe out the pan. Place the oil, mushrooms, onions, carrots, and garlic in the pan. Cook the vegetables, stirring frequently until the onions start to look translucent and the mushrooms start to soften. Add back the cooked ground meat, along with any juices that have accumulated at the bottom of the bowl back into the pan.

    Cook the mushrooms and vegetables until they start to soften.
  5. Pour in the chicken stock then add the tomato paste and sprinkle the flour over the mixture. Add the marmite and the salt, pepper, ground thyme and corn. Cook on medium heat, stirring constantly, for 10 minutes, until the filling has thickened. Stir in the frozen peas to the hot filling.

    Add the cooked ground lamb back to the pan and add the stock.
  6. Pour the entire filling into a 9 x 13 inch casserole dish or an oval 3-quart capacity dish. Spoon the mashed potatoes into a pastry bag fitted with a star tip, then pipe the mashed potatoes over the filling in strips. Or spoon the mashed potatoes over the filling and then use the back of the spoon to indent and create ridges in the mashed potatoes. You want to create as much surface area as possible so the mashed potatoes can crisp.

    Pour the filling into the baking pan, then pipe or spoon the mashed potatoes over it.
  7. Place the baking dish on a rimmed baking sheet (to catch any spills) and then place in the oven. Bake for 25 to 30 minutes or until the filling is bubbling up around the edges and the top of the mashed potatoes are golden brown. 

    Bake in oven until filling is bubbling on the sides and the top is golden brown.
  8. Let cool 10 minutes before serving warm.