Start by placing the cubed potatoes in a large pot and cover them with cold water. Bring to a boil.

In a large skillet, heat olive oil over medium heat and add chopped onions and carrots. Sauté until soft, about 5 minutes.

Stir in the ground lamb or beef, breaking it apart with a spatula. Cook until browned, about 7-10 minutes.

Add tomato paste, Worcestershire sauce, thyme, and broth to the meat mixture. Mix well.

Fold in the peas and let the mixture simmer for another 5 minutes.

Drain the boiled potatoes and return them to the pot. Mash with butter and milk until creamy, seasoning with salt and pepper.

Spread the meat mixture evenly in a baking dish and top with mashed potatoes. Use a fork to create peaks.

Preheat your oven to 400°F (200°C) and bake the Shepherd's Pie for 20 minutes or until the top is golden brown.

For an extra crispy topping, broil the pie for the last few minutes, keeping a close eye.