Ingredients:

  • 2 tablespoons olive oil (30 ml)
  • 1 large onion, diced (about 1 cup, 150g)
  • 2 carrots, diced (about 1 cup, 150g)
  • 2 celery stalks, diced (about 1 cup, 150g)
  • 1.5 lbs ground lamb or beef (680g)
  • 2 cloves garlic, minced
  • 1 teaspoon dried thyme
  • 1 teaspoon dried rosemary
  • 1/2 teaspoon salt
  • 1/4 teaspoon black pepper
  • 2 tablespoons all-purpose flour (25g)
  • 1 cup beef broth (240ml)
  • 1/2 cup frozen peas (80g)
  • 2 tablespoons Worcestershire sauce (30ml)
  • 1 tablespoon tomato paste (15g)
  • 3 lbs russet potatoes, peeled and quartered (1.36kg)
  • 1/2 cup milk (120ml)
  • 4 tablespoons unsalted butter (57g)
  • 1/2 cup sour cream (120g)
  • 1 cup shredded cheddar cheese (113g), divided
  • 1/4 teaspoon salt
  • 1/8 teaspoon black pepper

Instructions:

  1. Sauté onion, carrots, and celery in olive oil until softened.
  2. Add ground lamb or beef and cook, breaking it up, until browned. Drain off any excess fat.
  3. Stir in garlic, thyme, rosemary, salt, and pepper.
  4. Sprinkle flour over the meat mixture and cook for 1 minute. Gradually stir in beef broth, Worcestershire sauce, and tomato paste. Bring to a simmer and cook until thickened.
  5. Stir in frozen peas and remove from heat.
  6. Boil potatoes until tender. Drain and return to the pot.
  7. Mash potatoes with milk, butter, sour cream, salt, and pepper until smooth. Stir in 3/4 cup of the cheddar cheese.
  8. Pour the meat filling into the baking dish. Spread the mashed potato topping evenly over the meat.
  9. Sprinkle the remaining cheddar cheese over the potato topping.
  10. Bake in a preheated oven at 375°F (190°C) for 25-30 minutes, or until the topping is golden brown and the filling is bubbly.
  11. Let the casserole rest for 10 minutes before serving.