Preheat your oven to 400°F (200°C).
In a large skillet, heat olive oil over medium heat.
Add chopped onions and cook until softened.
Stir in diced carrots and cook for another 5 minutes.
Add ground meat and cook until browned.
Mix in tomato paste and thyme, cooking for another minute.
Pour in beef broth and bring to a simmer.
Stir in peas and season with salt and pepper.
Spread the meat mixture in a baking dish.
Top with mashed potatoes, smoothing out the surface.
Bake in the preheated oven for 25 minutes or until golden brown.