1. Preheat your oven to 180°C or 356°F.

2. Peel the potatoes and slice them thinly.

3. In a large saucepan, combine the sliced potatoes, salt, and pepper, then add enough cold water to cover the potatoes and bring to a boil. Reduce the heat and simmer for 5 minutes. Drain the potatoes and set them aside.

4. Sauté sliced onions and minced garlic in a little bit of oil in a skillet until they are softened and lightly caramelized.

5. Combine the cooked potatoes, sautéed onions and garlic, and crumbled goat cheese in a large bowl. Mix well to combine.

6. Whisk together heavy cream and a pinch of salt in a separate bowl. Pour the cream mixture over the potato mixture and mix until the potatoes are well coated.

7. Transfer the potato mixture to a baking dish and top with fresh cheese, crumbled into small pieces.

8. Bake the gratin in the preheated oven for 30-40 minutes, or until the top is golden brown and the potatoes are cooked through.

9. Remove the gratin from the oven and let it rest for 10-15 minutes before serving. Serve hot and enjoy!