Preheat your oven to 180°C (350°F).

Heat olive oil in a large skillet over medium heat. Add finely chopped onion, diced carrots, and minced garlic. Sauté until the vegetables are softened, approximately 5 minutes.

Add ground beef to the skillet and cook until browned, using a wooden spoon to break it up.

Stir in tomato paste, beef stock, Worcestershire sauce, dried thyme, dried rosemary, salt, and pepper. Bring the mixture to a simmer and let it cook for about 10 minutes to allow the flavours to blend. Remove from heat.

In a separate pot, boil peeled and chunked potatoes in salted water until tender when pierced with a fork, about 15-20 minutes. Drain the potatoes and return them to the pot.

Add milk and butter to the pot with the potatoes. Mash them until smooth and creamy. Season with salt and pepper to taste.

Transfer the beef mixture to a baking dish and spread the mashed potatoes evenly on top. Optionally, sprinkle grated cheese over the mashed potatoes.

Bake in the preheated oven for 30-35 minutes, until the top is golden and the filling is bubbling.

Allow the cottage pie to cool for a few minutes before serving.

Serve the cottage pie hot and enjoy!