Potatoes au gratin is that rare side dish that feels equally appropriate at a fancy dinner party and on a Tuesday night at home with the family—that is to say, it’s incredibly easy to make, wonderfully decadent, and everyone loves it. Before you get started, be sure to pick up russet or Idaho potatoes for this recipe. Their starchy flesh makes them the best potatoes for soaking up the creamy sauce, while their sturdy skins keep the thin slices from falling apart. When simmering the cream, make sure it’s over a gentle heat (if it over-reduces, it will break). Slowly infusing and then blending it ensures that the flavors of garlic and fresh thyme reach every corner of the dish.
It’s the cheese (and sometimes an addition of bread crumbs) that differentiates a gratin from scalloped potatoes. While the latter is simply sliced potatoes baked in cream, this gratin recipe is topped with a generous helping of nutty Gruyère cheese and a touch of Parmesan. If you prefer a higher cheese quotient (we won’t blame you), this recipe for cheesy au gratin potatoes is loaded with sharp cheddar cheese and gets a subtle kick from cayenne pepper.
Editor’s note: This recipe was originally published October 20, 2015.
Recipe information
Total Time
2 hours
Yield
12 Servings
Ingredients
Preparation
Step 1
Preheat oven to 325°. Cut 1 garlic clove in half and rub the inside of a 3-qt. shallow baking dish with cut sides. Smear butter all over inside of dish. Bring shallots, cream, salt, pepper, 1 Tbsp. thyme, and remaining 4 garlic cloves to a simmer in a small saucepan over low heat; cook until shallots and garlic are very soft, 15–20 minutes. Let cool slightly. Transfer to a blender; blend until smooth.
Step 2
Arrange potato slices in prepared dish, fanning out a handful at a time and placing in dish at an angle (this ensures every scoop will have tender potatoes from the bottom and crisp edges from the top). Shingle as you work until bottom of dish is covered. Tuck smaller slices into any gaps to fill. Pour cream mixture over potatoes and cover dish tightly with foil. Bake potatoes until tender and creamy, 60–75 minutes. Let cool.
Step 3
Place rack in highest position; heat broiler. Remove foil and top potatoes with Gruyère and Parmesan. Broil until cheese is bubbling and top of gratin is golden brown, 5–10 minutes. Serve topped with more thyme leaves.
Do Ahead: Gratin can be baked 1 day ahead. Cover and chill. Bring to room temperature before broiling.
