Preheat your oven to 400°F (200°C).
In a large skillet, heat olive oil over medium heat.
Add diced onion and cook until translucent, about 5 minutes.
Stir in minced garlic and diced carrots; cook for 3 minutes.
Add ground meat, breaking it apart, and cook until browned.
Stir in tomato paste and Worcestershire sauce.
Pour in broth and bring to a simmer.
Add frozen peas and season with salt and pepper; cook for 5 more minutes.
Transfer the meat mixture to a baking dish.
Top with mashed potatoes, spreading evenly.
Bake in the oven for 25-30 minutes, until the top is golden brown.