# What You'll Need:
→ Filling
01 - 2 tablespoons olive oil
02 - 1 large onion, finely chopped
03 - 2 carrots, peeled and diced
04 - 2 celery stalks, diced
05 - 2 cloves garlic, minced
06 - 1.1 pounds ground lamb
07 - 2 tablespoons tomato paste
08 - 2/3 cup beef or lamb stock
09 - 1 tablespoon Worcestershire sauce
10 - 1 teaspoon dried thyme
11 - 1 teaspoon dried rosemary
12 - 1 cup frozen peas
13 - Salt and freshly ground black pepper, to taste
→ Cheesy Potato Topping
14 - 2.6 pounds potatoes, peeled and cut into chunks
15 - 1/4 cup milk
16 - 3.5 tablespoons unsalted butter
17 - 1 cup mature cheddar cheese, grated
18 - Salt and pepper, to taste
# How to Make It:
01 - Set oven temperature to 400°F.
02 - Bring a large saucepan of salted water to a boil. Add prepared potatoes and simmer until completely tender, about 15 to 20 minutes.
03 - Meanwhile, heat olive oil in a large skillet over medium heat. Add onion, carrot, and celery; cook for 6 to 8 minutes until softened.
04 - Add minced garlic and cook for 1 minute. Stir in ground lamb, breaking up with a wooden spoon, and brown for approximately 8 minutes.
05 - Drain excess fat from skillet. Add tomato paste and stir to evenly combine. Pour in stock and Worcestershire sauce, then add thyme and rosemary. Simmer for 10 minutes until the mixture thickens.
06 - Stir in frozen peas and season generously with salt and black pepper. Remove from heat and set aside.
07 - Drain cooked potatoes and return to saucepan. Mash thoroughly with milk and unsalted butter until smooth. Fold in half the grated cheddar cheese and season to taste.
08 - Transfer lamb filling into a deep baking dish (2-quart capacity). Spread mashed potatoes over filling, smoothing surface. Sprinkle remaining cheddar cheese on top.
09 - Place filled baking dish in oven. Bake for 25 to 30 minutes until the potato topping turns golden and the filling is bubbling.
10 - Remove from oven and allow to rest for 10 minutes prior to serving.
