Preheat your oven to 375°F (190°C) and grease a large casserole dish with butter.
Brown the ground meat in a skillet. Add onions and garlic until soft, then the peas, carrots, herbs, salt, and pepper.
Sprinkle flour over the mixture, add broth and tomato paste, and cook until thickened.
In a separate bowl, mix heavy cream, half the cheese, salt, and pepper.
Layer half the potatoes in the dish, top with the cream mixture, then the meat mixture, followed by remaining potatoes, and the rest of the cream mixture.
Cover and bake for 40 minutes. Uncover, add remaining cheese, and bake until golden and potatoes are tender.
Let rest for 10 minutes, garnish, and serve.