1. Preheat your oven to 190°C or 375°F.

2. Peel the potatoes and slice them into 3 mm or 1/8-inch thick rounds.

3. In a large saucepan combine 250ml or 1 cup of heavy cream, a pinch of salt, and a vegetable broth cube. Bring the mixture to a boil then reduce the heat to medium-low and simmer for 5 minutes.

4. In a large skillet sauté sliced onions in a little oil until they're softened and caramelized. Add minced garlic and cook for an additional minute.

5. In a greased 23x33 cm or 9x13-inch baking dish create a layer of potatoes. Top with a layer of caramelized onions, a sprinkle of grated cheese, and a dollop of the creamy sauce. Repeat this process until all the ingredients are used, finishing with a layer of cheese on top.

6. Cover the dish with aluminum foil and bake for 45 minutes. Remove the foil and continue baking for an additional 15-20 minutes or until the top is golden brown and the potatoes are tender.

7. Remove the dish from the oven and let it cool for 10 minutes before serving.