Preheat your oven to 400°F (200°C). Peel and dice the potatoes, then place them in a large pot covered with cold water. Bring to a boil.

Reduce the heat to medium and let the potatoes simmer for about 15 minutes until fork-tender. Drain and return to pot.

Mash the potatoes with butter and milk until creamy, seasoning with salt and pepper to taste.

In a skillet over medium heat, cook the ground lamb until browned, about 5-7 minutes.

Add the diced onion and minced garlic to the skillet with the lamb, cooking for about 5 minutes until soft.

Stir in the tomato paste, cook for an additional minute, then add beef stock and Worcestershire sauce, stirring to combine.

Add frozen peas and carrots, simmer for about 5 minutes. Season with salt and pepper as needed.

Spread the meat mixture in a baking dish, dollop mashed potatoes on top, creating peaks.

Bake in the preheated oven for about 20 minutes until the top is golden brown.

Let cool for 5 minutes before serving. Enjoy!