Potato and Minced Beef Gratin

1.Preheat your oven to 190°C (375°F) and lightly grease a large baking dish with butter or oil.

2.In a large skillet, heat the olive oil over medium heat. Add the sliced onions and cook for 12-15 minutes, stirring occasionally, until they are soft and deeply caramelized.

3.Add the minced beef to the skillet with the onions. Increase the heat to medium-high and cook until the beef is browned, breaking it up with a wooden spoon.

4.Stir in the garlic, tomato paste, thyme, salt, and pepper. Cook for another 2 minutes until fragrant, then remove from heat and set aside.

5.In a medium bowl or jug, whisk together the heavy cream, milk, nutmeg, and a pinch of salt and pepper to create the sauce.

6.Arrange half of the thinly sliced potatoes in an overlapping layer at the bottom of the prepared baking dish.

7.Spread the seasoned beef and onion mixture evenly over the first layer of potatoes, then sprinkle with half of the shredded Gruyère cheese.

8.Layer the remaining potato slices on top of the beef. Pour the cream mixture evenly over the entire dish, ensuring it seeps between the layers.

9.Top with the remaining Gruyère and the grated Parmesan cheese.

10.Cover the dish with foil and bake for 40 minutes. Remove the foil and bake for an additional 20-25 minutes until the potatoes are tender and the cheese topping is golden brown and bubbling.

11.Let the gratin rest for 10 minutes before garnishing with fresh parsley and serving.