Rich, comforting shepherd's pie with seasoned ground lamb (or beef), vegetables, and creamy mashed potatoes baked under a golden Gruyere cheese crust. The ultimate family dinner.
Place peeled and cubed potatoes in a large pot of salted water. Bring to a boil and cook until fork tender, about 15-18 minutes. Drain well.
Mash the cooked potatoes until smooth, then add butter, sour cream, half and half, salt, and pepper. Mix until creamy and fluffy. Set aside.
Heat a large skillet over medium-high heat. Add the ground lamb or beef and cook until browned, breaking it apart with a spatula. Drain excess fat if necessary.
Add the diced onion and carrots. Cook for about 5 minutes until softened. Stir in the garlic and cook for another 30 seconds.
Stir in the tomato paste, Worcestershire sauce, rosemary, and thyme. Cook for 1-2 minutes to caramelize the tomato paste.
Sprinkle in the flour and stir well. Slowly pour in the beef broth while stirring. Let it simmer until it thickens into a rich gravy, about 3-4 minutes.
Stir in the frozen corn and peas. Simmer for 3-4 minutes. Adjust seasoning with salt, pepper, garlic powder, and onion powder.
Preheat oven to 400°F. Spread the meat filling evenly in a baking dish. Top with mashed potatoes, spreading evenly. Use a fork to create ridges for texture.
Sprinkle with Gruyere or Parmesan cheese. Bake for 20-25 minutes until golden and bubbling. Broil for 2-3 minutes at the end for extra browning.
Let rest for 5-10 minutes before serving. Garnish with fresh chopped parsley.
Notes
For make-ahead: Assemble, cover with foil, and refrigerate up to 24 hours. Add 10-15 extra minutes bake time from the fridge.Freezer-friendly: Wrap tightly and freeze up to 3 months. Thaw overnight before baking.You can substitute ground beef for ground lamb or use a blend of both.