Ingredients
For the Meat Filling:
- 2 pounds ground lamb (or ground beef for cottage pie)
- 1 large onion, finely diced
- 2 medium carrots, peeled and diced small
- 2 celery stalks, finely chopped
- 3 cloves garlic, minced
- 2 tablespoons tomato paste
- 2 cups beef or lamb stock (low-sodium preferred)
- 1 cup frozen peas
- 2 tablespoons Worcestershire sauce
- 1 teaspoon fresh thyme leaves (or ½ teaspoon dried)
- 1 teaspoon fresh rosemary, chopped (or ½ teaspoon dried)
- 2 tablespoons all-purpose flour
- 2 tablespoons olive oil
- Salt and black pepper to taste
For the Potato Topping:
- 3 pounds russet or Yukon gold potatoes, peeled and quartered
- ½ cup whole milk, warmed
- 4 tablespoons unsalted butter
- ½ cup sour cream (or Greek yogurt)
- 1 cup shredded cheddar cheese, divided
- 1 teaspoon garlic powder
- Salt and pepper to taste
Instructions
- Prepare the Potatoes: Place quartered potatoes in a large pot and cover with cold, salted water. Bring to a boil over high heat, then reduce to medium and simmer for 15-20 minutes until fork-tender.
- Build the Flavor Base: Heat olive oil in a large, deep skillet or Dutch oven over medium-high heat. Add diced onion, carrots, and celery, sautéing for 6-8 minutes until vegetables soften and onions turn translucent. Add minced garlic during the final minute, stirring constantly.
- Brown the Meat and Create the Filling: Push vegetables to the sides and add ground lamb to the center. Break apart with a wooden spoon and cook for 8-10 minutes until deeply browned. Sprinkle flour over the meat and stir for 1 minute. Add tomato paste, Worcestershire sauce, herbs, stock, salt, and pepper. Simmer uncovered for 15-20 minutes until sauce thickens. Stir in frozen peas during the last 3 minutes.
- Whip Up Creamy Mashed Potatoes: Drain cooked potatoes thoroughly and return to the hot pot for 1 minute to evaporate excess moisture. Add butter, warm milk, sour cream, half the cheese, garlic powder, salt, and pepper. Mash until smooth and creamy. Taste and adjust seasoning.
- Assemble and Bake: Preheat oven to 400°F (200°C). Transfer meat filling to a 9×13-inch baking dish, spreading evenly. Dollop mashed potatoes on top and spread from center outward. Use a fork to create decorative ridges. Sprinkle remaining cheese over top. Bake for 25-30 minutes until golden brown and filling bubbles around edges. Let rest for 10 minutes before serving.
Notes
Storage Tips:
- Refrigerate leftovers in airtight containers for up to 4 days
- Freeze unbaked for up to 3 months or baked for up to 2 months
- Reheat at 350°F covered with foil for 25-30 minutes
Substitutions:
- Use ground beef instead of lamb for cottage pie
- Swap half the potatoes with cauliflower for lower carbs
- Use ground turkey for a leaner option
- Make it vegetarian with plant-based meat or lentils
Tips:
- Don’t skip the resting time – it helps the filling set for clean portions
- Create peaks with a fork on the potato topping for extra crispy bits
- Ensure your filling is thick before assembling to avoid watery results
- Prep Time: 25 minutes
- Cook Time: 55 minutes
- Category: Main Course
- Method: Baking
- Cuisine: British
- Diet: Gluten Free
