Savory Potato and Onion Gratin

1Preheat your oven to 375°F (190°C).

2Grease a 9x13 inch baking dish with unsalted butter (2 tablespoons).

3In a large bowl, combine the heavy cream (2 cups), minced garlic (2 cloves), thyme, salt (1 teaspoon), and black pepper (½ teaspoon). Mix well.

4Layer half of the sliced potatoes (4 large) in the bottom of the prepared baking dish, followed by half of the sliced onions (2 large).

5Pour half of the cream mixture over the first layer of potatoes (4 large) and onions (2 large), then sprinkle with half of the Gruyère and Parmesan cheeses.

6Repeat the layering process with the remaining potatoes (4 large), onions (2 large), cream mixture, and cheeses, finishing with a layer of cheese on top.

7Cover the baking dish with aluminum foil and bake in the preheated oven for 45 minutes.

8After 45 minutes, remove the foil and bake for an additional 30 minutes, or until the top is golden brown and the potatoes (4 large) are tender when pierced with a fork.

9Let the gratin cool for a few minutes before serving. Enjoy your savory potato and onion gratin!