Equipment
* optional
Ingredients
Aromatics & Dairy
- 2 garlic, 1 clove halved, 1 clove minced
- 15 g unsalted butter, softened
- 300 ml heavy cream
- 300 ml whole milk
- 12 g kosher salt
- 2 g black pepper, freshly ground
- 1 g nutmeg, freshly grated
Potatoes
- 1000 g russet potato, peeled
Nutrition (per serving)
Method
Preheat the oven to 200°C/400°F. Rub the inside of a gratin dish thoroughly with the halved garlic clove to release its essential oils, then generously grease the dish with the softened butter.
Slice the peeled russet potatoes uniformly to about 3mm thick using a mandoline slicer. Do not wash or rinse the potatoes after slicing, as retaining the surface starch is critical for the sauce to emulsify and thicken.
In a large wide saucepan, combine the heavy cream, whole milk, minced garlic clove, kosher salt, black pepper, and nutmeg. Bring the mixture to a gentle boil over medium heat.
Add the sliced potatoes to the boiling liquid. Reduce the heat and simmer gently for 8 to 10 minutes, stirring occasionally with care to avoid breaking the slices. The liquid should thicken slightly as the potato starch releases.
Carefully transfer the potato and cream mixture into the prepared gratin dish, spreading the potato slices into an even, compact layer.
Bake in the preheated oven for 30 to 35 minutes until the potatoes are completely tender when pierced with a paring knife and the top has formed a deep golden brown, bubbling glaze.
Remove from the oven and let the gratin rest for 10 to 15 minutes before serving. This resting period is non-negotiable, as it allows the bubbling cream mixture to cool slightly and set into a cohesive sauce.
Chef's Notes
- The hallmark of a Michelin-level Gratin Dauphinois is the strict absence of cheese. A quality mixture of heavy cream and whole milk naturally reduces in the high heat of the oven to form a perfectly glazed, deeply savory crust.
- Never wash your potato slices. Russet potatoes are naturally high in amylose starches, which act as the sole thickening agent for the liquid. Rinsing them will result in a watery, separated sauce.
- Simmering the potatoes in the cream mixture prior to baking is a classic French restaurant trick. It kickstarts the starch release, seasons the potatoes internally, and cuts the traditional two-hour oven baking time in half.
- Do not skimp on the resting step. The sauce will appear dangerously thin immediately out of the oven, but it rapidly thickens into a rich, velvety consistency as it cools to serving temperature.
Storage
Refrigerator: 4 days — Store covered. Reheats beautifully and often tastes better the next day as flavors meld.
Reheating: Reheat in a 150°C/300°F oven until warmed through and bubbling at the edges.
