Preheat your oven to 400°F (200°C).
In a large skillet, heat olive oil over medium heat.
Add chopped onions and cook until translucent.
Stir in minced garlic and cook for another minute.
Add ground beef or lamb and cook until browned.
Mix in diced carrots, peas, and tomato paste.
Pour in the beef broth and simmer for 10 minutes.
Season the mixture with salt and pepper to taste.
Transfer the meat mixture to a baking dish.
Spread mashed potatoes evenly on top and create peaks with a fork.
Bake in the preheated oven for 25-30 minutes until golden brown.
Let cool slightly before serving.