Creamy Potato Gratin with Gruyère and Thyme
Thinly sliced potatoes baked in garlicky cream and nutty Gruyère until tender, bubbling and deeply golden on top. A show-stopping side for any holiday table.
- Prep
- 20 min
- Cook
- 70 min
- Total
- 1 hr 30
- Serves
- 8
Even slices are the secret, so use a mandoline if you have one. The gratin can be baked a day ahead, chilled, and reheated covered at 350°F for 25 minutes. Resting before cutting gives clean squares.
Method
-
Heat the oven to 375°F (190°C) and butter a 9x13-inch baking dish.
-
Warm the cream, milk, garlic, salt, pepper, nutmeg and 4 thyme sprigs in a saucepan over medium-low heat until steaming. Remove from the heat, let it steep for , then discard the garlic and thyme.
-
Slice the potatoes 1/8 inch thick with a mandoline or sharp knife. Do not rinse them, since the starch helps thicken the sauce.
-
Layer a third of the potatoes in the dish, overlapping slightly. Scatter with a third of the Gruyère and pour over a third of the cream. Repeat twice more, finishing with cream.
-
Press the potatoes down so they are mostly submerged, then cover tightly with foil and bake for .
-
Remove the foil, sprinkle with the Parmesan and bake more until deep golden and a knife slides in with no resistance.
-
Rest for so the sauce sets, then scatter with the leaves from the remaining thyme and serve.
Tap a number to check off a step. Tap a green time to start a timer.
