Preheat your oven to 400°F (200°C).

In a skillet, heat olive oil over medium heat. Sauté the chopped onion and diced carrots until soft, about 5 minutes.

Add minced garlic and cook for an additional minute. Incorporate ground beef or lamb, breaking it apart and brown for about 5-7 minutes.

Stir in tomato paste, beef broth, Worcestershire sauce, thyme, rosemary, salt, and pepper. Simmer for about 10 minutes.

Transfer meat mixture to a baking dish, layer frozen peas over it, and spoon the mashed potatoes on top.

Create texture on the potato layer using a fork.

Bake for 25-30 minutes until the top is golden brown and bubbling.

Let it rest for about 5-10 minutes before serving.