My sister passed down this creamy holiday side and it only takes 4 ingredients to make

My sister first brought this pan of bubbling, golden potatoes to our family Christmas back in the late seventies, and it’s been on our holiday table ever since. It’s the kind of old-fashioned Midwestern comfort food that feels special but doesn’t ask much of you—just four simple ingredients and a little patience while the oven does its work. Thinly sliced potatoes soak up rich cream and melt into a silky, spoonable casserole, while a blanket of Gruyere turns crisp and deeply browned on top. This is the dish I reach for when I want something trustworthy, cozy, and pretty enough to carry straight from the oven to the table.

These Gruyere au gratin potatoes are rich and creamy, so they shine alongside simple main dishes: roasted turkey, baked ham, pot roast, or a pan-seared pork chop all work beautifully. I like to balance the richness with something green and bright, like steamed green beans, a tossed salad with a sharp vinaigrette, or roasted Brussels sprouts. A basket of warm dinner rolls or crusty bread is handy for scooping up the last bits of cream and cheese from the casserole dish.

Servings: 6

2 1/2 pounds russet or Yukon Gold potatoes, peeled and very thinly sliced

Heat the oven to 375°F (190°C). Lightly butter or spray a 2-quart glass casserole dish; this helps keep the potatoes from sticking and makes cleanup easier.

Peel the potatoes and slice them as thinly as you comfortably can, about 1/8 inch thick. A mandoline makes quick work of this, but a sharp knife and a steady hand are just fine. Try to keep the slices roughly the same thickness so they cook evenly.

In a large bowl, gently toss the sliced potatoes with the salt, using your hands to separate any pieces that want to cling together. This seasons the whole dish without needing anything extra.

Layer about one-third of the potatoes in the bottom of the prepared casserole dish, overlapping the slices slightly like shingles on a roof. Sprinkle one-third of the shredded Gruyere over the potatoes. Repeat with a second layer of potatoes and a second layer of Gruyere, then finish with the remaining potatoes, saving the last third of the cheese for the top.

Slowly pour the heavy cream over the layered potatoes, aiming to distribute it evenly so it seeps down between the slices. Gently press down on the potatoes with the back of a spoon or your clean hands to settle them into the cream and remove any large air pockets.

Sprinkle the remaining Gruyere evenly over the top. Place the casserole dish on a rimmed baking sheet to catch any bubbling cream that might spill over in the oven.

Bake, uncovered, for 50 to 65 minutes, until the potatoes are very tender when pierced with a knife and the top is deeply golden brown and bubbling around the edges. If the top is browning too quickly before the potatoes are tender, loosely tent the dish with foil and continue baking until done.

Remove the casserole from the oven and let it rest for at least 10 to 15 minutes before serving. This short rest allows the cream to thicken slightly and makes it easier to spoon out neat portions while keeping that lovely, crisp Gruyere lid on top.

If your family likes a little extra saltiness, you can sprinkle a small handful of finely grated Gruyere between the layers and keep the top amount the same, but be careful not to add more ingredients if you want to honor the simple four-ingredient spirit of this dish. For a slightly sturdier texture, use Yukon Gold potatoes; for a softer, more melting texture, use russets. You can also adjust the richness by using 1 1/2 cups cream and 1/2 cup whole milk, though it won’t be quite as luxurious. To make this ahead, assemble the dish up to a day in advance, cover, and refrigerate; add 10 to 15 minutes to the baking time and remove the cover for the last half of baking so the top can brown. If your oven browns unevenly, rotate the dish halfway through. Leftovers reheat nicely, covered, in a 325°F oven until warmed through, and they’re wonderful alongside a simple green salad for lunch the next day.