This dish has been my answer to every gathering where people ask for something hearty, creamy, and unpretentiously elegant. I discovered this version during a chilly November when I wanted to combine the mellow depth of roasted garlic with the silky melt of a cheese-bathed potato bake. The result is an inviting balance of tender, starchy potato ribbons and a lusciously seasoned cream that browns into a crisp, golden top. Every time I pull this from the oven the kitchen fills with a warm, savory aroma that makes friends and family drift in from other rooms. I first served it at a small dinner where I swapped my usual casserole for an upright-layered presentation. It felt almost celebratory the way the edges crisped and the center stayed pillowy soft. The roasted garlic becomes sweet and nutty, folding into the cream so it tastes like the whole heart of the head of garlic has been liquefied into comfort. Texturally the contrast between the tender slices and the melted, slightly caramelized cheese is what keeps everyone going back for seconds.

Ingredients

• Potatoes: Use 8 to 9 medium starchy potatoes (about 2 lb 10 oz total). Look for russets or Yukon Golds; russets produce a fluffier interior while Yukon Golds add buttery flavor and hold their shape beautifully when sliced thin.
• Garlic: One whole head. Roasting transforms sharp raw garlic into a sweet, spreadable paste that blends seamlessly into the cream base. Choose firm heads without sprouting cloves.
• Heavy cream: 1 cup for a rich, silky sauce that sets as it bakes; full-fat dairy helps the top brown and the interior stay moist.
• Whole milk: 1/4 cup to slightly loosen the cream so it seeps between the layers. If you only have 2 percent, it will still work.
• Butter: 1 tablespoon unsalted for greasing the dish and enriching the cream; unsalted lets you control seasoning.
• Fresh thyme: 1 teaspoon of leaves for bright, herbaceous notes; alternatively use 1/4 teaspoon dried thyme.
• Nutmeg: 1/4 teaspoon freshly grated for a whisper of warmth that complements the dairy.
• Cheese: 2 cups shredded Gruyère or mozzarella plus 1/2 cup grated Parmesan. Gruyère lends nuttiness and a supple melt; mozzarella gives extra stretch while Parmesan adds savory depth.
• Salt and pepper: To taste. I recommend kosher salt and freshly cracked black pepper for clarity of seasoning.
• Olive oil: 1 tablespoon to drizzle over the garlic before roasting.
• Fresh chives: For garnish, thinly sliced to add a pop of color and oniony brightness at the end.

Instructions

Preheat and Roast Garlic: Preheat the oven to 375°F (190°C). Trim the top off the garlic head to expose the tips of the cloves. Drizzle with about 1 tablespoon olive oil, sprinkle a pinch of salt, wrap tightly in foil, and roast on a baking sheet for 30 to 35 minutes until cloves are very soft and caramelized. Allow to cool slightly so you can squeeze the softened cloves into a paste. Prepare the Dish: Grease a 9 by 13 inch baking dish with 1 tablespoon unsalted butter. Using a mandoline or a very sharp knife, slice potatoes paper-thin, about 1.5 to 2 millimeters thick (approximately 1/16 to 1/8 inch). Pat slices dry with a clean kitchen towel if they are wet; this helps the cream cling to the potato surfaces. Layer the Potatoes: Arrange potato slices upright and slightly overlapping in the greased dish so they stand like little shingled rows; this upright layering helps them cook evenly and exposes more surface area to the cream and heat, giving an attractive presentation and consistent texture. Make the Cream Mixture: In a small saucepan over low heat combine 1 cup heavy cream, 1/4 cup whole milk, 1 tablespoon butter, 1/2 cup grated Parmesan, 1 teaspoon fresh thyme leaves, 1/4 teaspoon nutmeg, and a generous pinch of salt and freshly ground pepper. Warm gently until the butter melts and the Parmesan begins to integrate, stirring so the mixture is smooth but not boiling. Combine with Roasted Garlic: Squeeze the roasted garlic cloves into a paste and whisk them into the warm cream. Taste and adjust seasoning; a little extra pepper highlights the garlic and cheese. Bake Covered: Pour the garlic-cream mixture evenly over the potatoes, press the potatoes gently down so the cream seeps into the layers, cover the dish tightly with foil, and bake for about 40 minutes. This initial covered baking steams the potatoes through without over-browning the top. Finish Uncovered: Remove foil, sprinkle the remaining 2 cups shredded Gruyère or mozzarella evenly over the surface, and return to the oven uncovered for 25 to 35 minutes until the top is golden brown, bubbling, and you see edges caramelize. Insert a knife to test tenderness; potatoes should be fork-tender. Rest and Serve: Let the casserole rest 10 to 15 minutes before serving so the sauce sets slightly. Garnish with chopped fresh chives and serve warm alongside roasted meats or a crisp green salad.

Storage Tips

Store leftovers in an airtight container in the refrigerator for 3 to 4 days. For best texture, reheat individual portions in a 350°F (175°C) oven on a baking sheet covered with foil for 15 to 20 minutes, then remove foil for 5 minutes to restore surface crispness. To freeze, cool completely, wrap tightly in plastic and foil, and freeze for up to 3 months. Thaw in the refrigerator overnight before reheating; you may need to add 5 to 10 minutes to the reheating time to ensure the center warms through.

Ingredient Substitutions

If Gruyère is unavailable, Emmental, Comte, or a high-quality white cheddar are excellent substitutes; mozzarella can be used for milder melt and lower salt. For a lighter version swap half-and-half for heavy cream, though the finish will be less decadent and may require slightly longer baking to thicken. Replace nutmeg with a pinch of smoked paprika for a subtler, warmer note. Use garlic powder only in a pinch; it cannot replicate the buttery sweetness of roasted garlic.

Serving Suggestions

Serve with roasted or braised meats such as beef short ribs, roasted chicken, or a maple-glazed ham. For a lighter meal, pair with a crisp green salad dressed in lemon vinaigrette or a simple sauté of green beans tossed with toasted almonds. Garnish with snipped chives or finely chopped parsley for color. This preparation also works as a centerpiece for holiday spreads, complementing cranberry or apple-based side dishes.

Cultural Background

This style of layered, cheese-topped potatoes traces its roots to classic French households where gratins were a way to stretch rich ingredients and celebrate simple produce. The French term roughly translates to a dish with a browned crust, often achieved with cheese or breadcrumbs. Versions of gratin evolved across regions, sometimes featuring cream-heavy sauces in Alpine areas where cows produced abundant high-fat milk and cheeses such as Gruyère and Comte became local staples.

Seasonal Adaptations

In winter, add a handful of roasted root vegetables like parsnips or rutabaga thinly sliced into the layers for extra heartiness. In spring and summer, layer in blanched asparagus tips or baby spinach for brightness; reduce cream slightly to keep the dish from feeling too heavy. For holiday tables, fold in a tablespoon of finely chopped fresh sage into the cream to complement turkey or goose.

Meal Prep Tips

Assemble the dish up to 24 hours ahead and keep covered in the refrigerator. Bring it to room temperature for 20 minutes before baking to reduce oven time and promote even cooking. If baking from chilled, add 10 to 15 minutes to the covered baking time. Use a mandoline with the guard on for safe, consistent slices, or ask your grocer to slice firm potatoes thinly if you prefer to skip the prep.

This gratin is one of those reliable, comforting dishes that rewards attention to small details: thin, even slices, gently warmed cream, and roasted garlic folded in at the end. It is both a practical weeknight upgrade and a celebration-worthy side that invites conversation and seconds. Try it once and you will have a new staple for everything from potlucks to quiet Sunday suppers.