Follow these steps to bring this classic dish to life in your own kitchen:

1. Preheat your oven to 375°F. Lightly butter a large baking dish to prevent sticking.
2. In a saucepan over medium heat, combine the heavy cream, minced garlic, salt, black pepper, and cayenne pepper. Bring to a simmer, stirring occasionally.
3. Reduce the heat to low and whisk in the Gruyère and Parmesan cheeses until melted and smooth. This cheesy sauce was always a favorite in my family, its aroma filling the kitchen with promises of deliciousness to come.
4. Layer half of the sliced potatoes evenly in the prepared baking dish. Pour half of the cheese sauce over the potatoes, spreading it evenly.
5. Repeat with the remaining potatoes and cheese sauce, ensuring the top layer is well covered for that signature golden crust.
6. Cover the dish with foil and bake for 45 minutes. Remove the foil and bake for an additional 15 minutes, or until the top is bubbly and golden.
7. Let the dish cool slightly before serving, garnished with fresh thyme or parsley for a pop of color and freshness.