Spring Supper Bake: Just 4 ingredients. Perfect for those nights when you want the oven to do all the thinking.

This Spring Supper Bake is my kind of weeknight comfort food: four ingredients, one pan, and the oven does all the thinking. It’s a retro-style creamed potato casserole, but with pretty sliced purple potatoes for a fun twist. Think scalloped potatoes minus the fussy roux—just layer, pour, and walk away while everything turns bubbly, creamy, and golden-brown on top. It’s perfect for those evenings when you’re juggling work emails and soccer practice but still want something cozy and homemade on the table.

Serve this creamy purple potato casserole as a cozy side with simple roasted chicken, seared pork chops, or a pan-fried steak. It also works as a vegetarian main if you add a crisp green salad with a tangy vinaigrette to cut through the richness. I like to spoon it next to steamed green beans or roasted asparagus for color and freshness. A glass of crisp white wine or sparkling water with lemon balances the creamy, caramelized edges really nicely.

Servings: 4-6

2 pounds purple potatoes, scrubbed and thinly sliced (about 1/8 inch)

Preheat your oven to 375°F (190°C). Lightly grease a medium casserole dish (about 8x8-inch or similar size) with a dab of neutral oil or butter if you have it on hand; this doesn’t count as an ingredient, just helps with cleanup.

Slice the scrubbed purple potatoes as thinly and evenly as you can, about 1/8 inch thick. You can use a sharp knife or a mandoline if you’re comfortable with one. Thinner, even slices help the casserole cook through and get that creamy, tender texture.

In a large measuring cup or bowl, whisk together the heavy cream, kosher salt, and black pepper until the seasoning is evenly distributed. This simple seasoned cream is what gives the casserole that retro creamed potato vibe without any extra steps.

Layer about one-third of the sliced potatoes in the bottom of the greased casserole dish, overlapping the slices slightly like shingles. Give the cream mixture a quick stir, then pour about one-third of it evenly over the potatoes, making sure the edges get some cream so they don’t dry out.

Repeat with another one-third of the potatoes, overlapping them, then pour another one-third of the cream mixture over that layer. Finish with the remaining potatoes, arranging them in a slightly neater pattern on top if you’d like, and pour the rest of the cream over everything, gently pressing down any slices that are sticking up so they’re mostly coated.

Cover the dish tightly with foil and place it on a rimmed baking sheet to catch any bubbling cream. Bake covered for 45–50 minutes, until the potatoes are mostly tender when pierced with a knife and the cream is hot and starting to thicken around the edges.

Carefully remove the foil (watch for steam), then return the casserole to the oven uncovered. Continue baking for another 25–35 minutes, until the top is deeply caramelized, with golden-brown and darker crispy spots, and glossy patches of reduced cream bubbling around the edges. If the top is browning too quickly before the potatoes are fully tender, loosely tent with foil again for the last 10 minutes.

Once the casserole is bubbling and the potatoes are very tender all the way through, remove it from the oven. Let it rest for at least 10–15 minutes before serving. This rest time helps the creamy sauce thicken slightly so it’s not soupy and makes it easier to cut into neat scoops or squares. Serve warm, enjoying the contrast of the creamy interior and crispy, caramelized top.

For a little extra flavor without adding more official ingredients, you can rub the baking dish with a cut clove of garlic before greasing it, or sprinkle a pinch of dried thyme or nutmeg into the cream mixture if you already keep those on hand. If you’re not strictly sticking to four ingredients, a handful of shredded sharp cheddar, Gruyère, or Parmesan on top during the last 15 minutes of baking will give you an even more retro, au gratin-style finish. For a lighter version, you can swap half of the heavy cream for whole milk; just know it may not thicken quite as luxuriously and might brown a bit less deeply. If you want to prep ahead, you can assemble the casserole up to the point of baking, cover tightly, and refrigerate up to 8 hours, then bake straight from the fridge, adding 5–10 extra minutes to the covered bake time. Food safety tips: Always keep the heavy cream refrigerated until you’re ready to use it, and don’t leave the assembled but unbaked casserole at room temperature for more than 1–2 hours. Leftovers should be cooled, covered, and stored in the refrigerator within 2 hours of baking, and eaten within 3–4 days. Reheat portions in the oven at 350°F until hot in the center (165°F if you’re checking with a thermometer), which will help bring back some of the crisp top, or in the microwave for convenience. As with any hot casserole, be careful when removing foil to avoid steam burns, and use a sturdy baking sheet under the dish to catch spills and make it easier to move in and out of the oven.