Quick Recipe Version (TL;DR)
Quick Ingredients
- 2 tablespoons unsalted butter (for the pan)
- 1 garlic clove, peeled (for rubbing the pan)
- 4 pounds Yukon Gold potatoes (about 8–10 medium), peeled
- 2 1/2 cups heavy cream
- 1 cup whole milk
- 3 garlic cloves, minced (about 1 tablespoon)
- 2 teaspoons kosher salt
- 1/2 teaspoon black pepper
- 1/4 teaspoon ground nutmeg
- 2 teaspoons fresh thyme leaves (or 3/4 teaspoon dried thyme)
- 8 ounces Gruyère cheese, grated (about 2 packed cups)
Do This
- 1. Heat oven to 375°F (190°C). Butter a 9 x 13-inch baking dish; rub with a cut garlic clove.
- 2. Warm cream + milk with minced garlic, salt, pepper, nutmeg, and thyme until steaming (do not boil).
- 3. Slice peeled potatoes 1/8-inch thick (mandoline helps). Do not rinse.
- 4. Layer half the potatoes, pour on half the cream, sprinkle with half the Gruyère; repeat.
- 5. Cover tightly with foil; bake 45 minutes.
- 6. Uncover; bake 40 minutes until bubbling and deep golden, and potatoes are very tender.
- 7. Rest 20 minutes; cut into 12 neat squares and serve.
Why You’ll Love This Recipe
- Golden, bubbling, and creamy: The garlicky cream thickens into a luxurious sauce as the potatoes bake.
- Perfect for serving a crowd: Resting and cutting into squares makes it easy to portion, buffet-style.
- Big flavor with simple ingredients: Gruyère, thyme, and a hint of nutmeg make it taste special.
- Make-ahead friendly: Assemble ahead or bake and reheat without losing the creamy texture.
Grocery List
- Produce: 4 lb Yukon Gold potatoes, 4 garlic cloves, fresh thyme (optional but recommended)
- Dairy: unsalted butter, heavy cream, whole milk, Gruyère cheese
- Pantry: kosher salt, black pepper, ground nutmeg
Full Ingredients
For the baking dish
- 2 tablespoons unsalted butter, softened (for greasing)
- 1 garlic clove, peeled and halved (for rubbing the dish)
For the potatoes
- 4 pounds Yukon Gold potatoes (about 8–10 medium), peeled
For the garlicky cream
- 2 1/2 cups heavy cream
- 1 cup whole milk
- 3 garlic cloves, minced (about 1 tablespoon)
- 2 teaspoons kosher salt
- 1/2 teaspoon freshly ground black pepper
- 1/4 teaspoon ground nutmeg
- 2 teaspoons fresh thyme leaves (or 3/4 teaspoon dried thyme)
For the cheese layer
- 8 ounces Gruyère cheese, grated (about 2 packed cups)
Step-by-Step Instructions
Step 1: Preheat the oven and prep the baking dish
Arrange a rack in the center of the oven and preheat to 375°F (190°C).
Grease a 9 x 13-inch baking dish (or similar 3–4 quart dish) with 2 tablespoons unsalted butter. Rub the inside of the dish with the cut sides of 1 halved garlic clove to lightly perfume the buttered surface.
Optional for the neatest “hotel-pan squares”: Line the dish with parchment so you can lift the finished potatoes out after resting. Leave a bit of overhang on the long sides. (This is easiest in a straight-sided metal 9 x 13-inch pan, but it also works in many ceramic dishes.)
Step 2: Warm the garlicky cream mixture
In a medium saucepan, combine 2 1/2 cups heavy cream, 1 cup whole milk, 3 minced garlic cloves, 2 teaspoons kosher salt, 1/2 teaspoon black pepper, 1/4 teaspoon nutmeg, and 2 teaspoons thyme leaves.
Set over medium heat and warm, stirring occasionally, until the mixture is steaming and just beginning to form tiny bubbles around the edges, about 4–6 minutes. Do not boil. Remove from the heat.
Step 3: Slice the potatoes evenly
Slice the peeled potatoes into 1/8-inch (3 mm) rounds. A mandoline makes this fast and consistent; if you use one, use the hand guard and go slowly. If slicing by hand, aim for uniform thickness so everything cooks at the same rate.
Do not rinse the sliced potatoes. The surface starch helps the cream thicken into a silky sauce while baking.
Step 4: Layer potatoes, cream, and Gruyère
Build the gratin in two layers for even seasoning and clean portions:
Arrange half the potato slices in the prepared dish, overlapping slightly like shingles and leveling the surface as you go.
Pour over about half of the warm cream mixture (give it a quick stir first so the garlic and thyme are evenly distributed). Sprinkle with half of the grated Gruyère.
Repeat with the remaining potatoes, the remaining cream mixture, and the remaining Gruyère. Press down gently with your hands or a spatula so the top layer is mostly submerged; this helps the potatoes cook evenly.
Step 5: Bake covered until the potatoes start to soften
Cover the dish tightly with foil (tight coverage prevents the top from browning too quickly before the potatoes are tender).
Bake at 375°F (190°C) for 45 minutes.
Step 6: Uncover and bake until bubbling and deeply golden
Carefully remove the foil. Continue baking uncovered for 40 minutes, or until the cream is actively bubbling around the edges and the top is golden brown with some deeper toasted spots.
To check doneness, insert a thin knife into the center; it should slide in with very little resistance. If you want an exact check, the center should be around 205°F (96°C).
If the top is browning faster than the potatoes are softening, loosely tent with foil for the last 10–15 minutes.
Step 7: Rest, slice into squares, and serve
Set the pan on a cooling rack and let the gratin rest for 20 minutes. This rest time is key: the sauce thickens, the layers settle, and the pieces cut cleanly.
For “hotel-pan squares,” slice into a 3 x 4 grid to make 12 portions. Use a thin spatula to lift each square. If you used parchment, you can lift the whole slab out after resting and cut on a board for extra-neat edges.
Serve warm. Dauphinoise potatoes are rich, so they pair beautifully with roast chicken, beef, ham, or a big green salad.
Pro Tips
- Choose the right potato: Yukon Golds give you creamy texture and clean slices. Russets work too, but they’re more prone to breaking down (still delicious, just less tidy).
- Slice thickness matters: Keep slices at 1/8-inch. Thicker slices can take longer and may bake unevenly; thinner slices can turn jammy.
- Warm the cream first: Starting with steaming (not boiling) cream helps the gratin bake evenly and reduces the risk of a grainy sauce.
- Don’t skip the rest: Resting for 20 minutes is what turns “scoopable” gratin into neat, sliceable squares.
- For extra neat portions: Bake in a straight-sided metal 9 x 13-inch pan, line with parchment, and chill briefly (30–45 minutes) after cooling before cutting; then rewarm.
Variations
- Extra-herby: Add 1 teaspoon finely chopped rosemary or sage (in addition to the thyme). Use a light hand; strong herbs can take over.
- Onion layer: Add 1 cup very thinly sliced shallots or onion between the layers (toss with a pinch of salt first). It becomes sweet and tender as it bakes.
- Cheese swap: Replace half of the Gruyère with 4 ounces grated sharp white cheddar for a slightly tangier, more pronounced cheese flavor.
Storage & Make-Ahead
Refrigerate: Cool completely, cover, and refrigerate for up to 4 days.
Reheat: For best texture, reheat in a 350°F (175°C) oven, covered, until hot in the center, about 20–30 minutes. Uncover for the last 5 minutes to re-crisp the top. Individual portions can be microwaved, but the oven keeps the best texture.
Make ahead: You can assemble the dish up to 24 hours in advance. Cover and refrigerate. Before baking, let it sit at room temperature for 30 minutes, then bake as directed (you may need an extra 5–10 minutes if it’s very cold going into the oven).
Nutrition (per serving)
Approximate, based on 12 servings: 420 calories; 30 g fat; 30 g carbohydrates; 10 g protein; 2 g fiber; 600 mg sodium.
