Equipment
Ingredients
Aromatics and Liquids
- 300 ml heavy cream
- 200 ml whole milk
- 3 garlic, whole cloves
- 12 g kosher salt
- 2 g black pepper, freshly cracked
- 1 g ground nutmeg
Produce and Dairy
- 1000 g yukon gold potatoes, peeled
- 15 g unsalted butter, softened
- 150 g gruyere cheese, freshly grated
Nutrition (per serving)
Method
Preheat your oven to 175C/350F. Ensure an oven rack is placed in the middle position.
Vigorously rub the inside of the gratin dish with the cut sides of the halved garlic clove to release its oils, then coat the interior generously with the softened unsalted butter.
Using a mandoline slicer, cut the peeled potatoes into perfectly even slices about 3mm thick. Do not rinse the potatoes under water after slicing, as you need their natural surface starches to thicken the cream sauce.
In the medium saucepan, combine the heavy cream, whole milk, the two crushed garlic cloves, kosher salt, black pepper, and ground nutmeg. Whisk briefly, then bring to a gentle simmer over medium heat. Once simmering, immediately remove from heat.
Arrange half of the potato slices in the prepared gratin dish, overlapping them slightly like shingles. Sprinkle an even layer using half of the grated gruyere cheese.
Layer the remaining potato slices on top. Fish out and discard the crushed garlic cloves from the warm cream mixture, then pour the liquid evenly over the entire dish. Finish by topping with the remaining gruyere cheese.
Bake uncovered in the preheated 175C/350F oven for 60 to 75 minutes. The dish is done when the potatoes yield completely to a knife and the cheese has formed a deep golden, bubbling crust.
Remove the gratin from the oven and let it rest at room temperature for at least 15 minutes before serving. This crucial step allows the bubbling liquids to settle and the sauce to thicken into a creamy glaze.
Chef's Notes
- The starch released from the sliced potatoes is the natural thickener for the rich sauce. Rinsing them under water is the most common mistake home cooks make, resulting in a watery dish.
- While a sharp chef knife can be used, a mandoline slicer is highly recommended. It ensures completely uniform potato slices, which is the only way to guarantee perfectly even cooking throughout the layers.
- Allowing the gratin to rest for at least 15 minutes after baking is entirely non-negotiable. The temperature drop allows the starches to stabilize, preventing the dish from flooding your plate with hot cream.
- Gruyere provides a nutty, complex flavor that melts beautifully. For a slightly different authentic alpine flavor profile, substitute equal parts Comte or Emmental cheese.
Storage
Refrigerator: 4 days — Cover tightly with food wrap or store in an airtight container.
Freezer: 1 month — Texture may become slightly grainy upon thawing but the rich flavor remains excellent.
Reheating: Reheat in a 160C/320F oven until bubbling around the edges, or microwave individual portions until hot throughout.
