My aunt brought this to dinner last week and I could not believe how easy it was. A crowd pleaser that needs just 4 ingredients.

This oven baked 4-ingredients cheesy leek potatoes dish is exactly the kind of recipe my aunt shows up with at family dinners: it looks like you fussed, but it’s almost embarrassingly easy. Think of it as a pared‑down gratin with a Midwestern potluck soul—tender sliced potatoes layered with buttery leeks and plenty of white cheddar, all bubbling together in a simple cream base. It’s a practical, weeknight‑friendly take on classic potato bakes you’d find in French and Scandinavian cooking, but streamlined to four ingredients so you can get it in the oven without much thought.

Serve these cheesy leek potatoes alongside roasted chicken, pork tenderloin, or a simple seared steak—the creamy, savory layers make a great contrast to anything grilled or roasted. For a lighter meal, pair the casserole with a crisp green salad dressed in a sharp vinaigrette to cut through the richness, and maybe some steamed green beans or roasted Brussels sprouts. It also holds beautifully on a buffet table, so it’s ideal for potlucks and holiday spreads, where guests can scoop it up next to ham, turkey, or a hearty vegetable main.

Servings: 6

2 tablespoons unsalted butter, plus a little extra for greasing the dish

Preheat your oven to 375°F (190°C). Lightly butter a medium white ceramic casserole dish (about 2-quart capacity) to prevent sticking and help with browning.

Prepare the leeks by trimming off the dark green tops and root ends. Slice the white and light green parts into thin half-moons, then rinse them thoroughly in a bowl of cool water, swishing to remove any grit. Lift the leeks out and drain well on a clean towel.

In a medium skillet over medium heat, melt the 2 tablespoons of butter. Add the sliced leeks and a pinch of salt. Cook, stirring occasionally, until the leeks are soft, sweet, and just starting to turn golden at the edges, about 8–10 minutes. Turn off the heat and set aside.

Peel the potatoes and slice them into thin rounds, about 1/8 inch thick. The more even the slices, the more evenly they will cook. If you slice ahead, keep them in a bowl of cold water to prevent browning, then pat dry before layering.

In a small bowl or measuring cup, combine the heavy cream, kosher salt, and black pepper. Stir to blend—this seasoned cream is what will bind the potatoes, leeks, and cheese into a cohesive, custardy bake.

Assemble the casserole: Arrange a single, slightly overlapping layer of potato slices on the bottom of the buttered dish. Scatter a portion of the sautéed leeks over the potatoes, then sprinkle a generous handful of shredded white cheddar on top.

Repeat the layering with potatoes, leeks, and cheddar until you’ve used all the leeks and most of the cheese, finishing with a final layer of potatoes on top. Gently press down with your hands to compact the layers slightly.

Slowly pour the seasoned cream evenly over the potatoes, tilting the dish if needed so the cream seeps down through the layers. Sprinkle the remaining cheddar over the top, making sure the surface is well covered for a nicely melted, golden finish.

Cover the casserole loosely with foil (tent it so it doesn’t stick to the cheese) and bake in the preheated oven for 40 minutes. This covered time lets the potatoes steam and soften without drying out.

Remove the foil and continue baking for another 20–30 minutes, or until the potatoes are very tender when pierced with a knife and the top is bubbly and deep golden brown. If the top is browning too quickly before the potatoes are done, lay the foil back on loosely.

Once baked, let the cheesy leek potatoes rest for at least 10–15 minutes before serving. This short rest allows the cream and cheese to settle so the slices hold together when scooped, and it concentrates the flavors.

To serve, scoop generous portions from the casserole, making sure to dig down through the layers so everyone gets tender potatoes, silky leeks, and plenty of melted white cheddar in each serving.

To stay true to the four-ingredient spirit, think of the butter, cream, salt, and pepper as your basic kitchen staples, and play only with the main components. You can swap the white cheddar for Gruyère or a sharp aged cheddar for a deeper, nuttier flavor, or use a mix if you have odds and ends in the fridge. If you prefer a slightly lighter texture, replace up to half of the heavy cream with whole milk; just know the finished dish will be a bit less rich. For a more rustic presentation, leave the potato skins on—especially with thin-skinned Yukon Golds—which adds a little color and texture. If you’re cooking ahead for a party, bake the casserole until just tender, cool, and refrigerate; reheat covered at 350°F (175°C) until hot, then uncover for the last 10 minutes to re-crisp the top. Leftovers reheat well in the oven or a covered skillet over low heat, and they make an excellent base for a hearty brunch topped with a fried or poached egg.