My mother taught me the secret to this sweet and savory 4 ingredient bake and it disappears faster than the main course.

My mother taught me this little potato trick back when I was just learning to cook for Sunday suppers on the farm. It’s nothing fancy—just four humble ingredients tossed into a foil-lined pan—but the way the sweet onions melt down and hug those crisp-edged potatoes makes the whole house smell like home. The onions caramelize in the oven, turning sticky and sweet, while the potatoes roast up golden and tender inside. This simple Midwestern bake has a way of disappearing faster than the main course, and it’s the kind of dish you can pull together on a busy weeknight or for a big family gathering without fuss.

Serve these sweet onion roasted potatoes straight from the foil-lined pan while they’re still sizzling and crisp around the edges. They’re wonderful alongside roast chicken, meatloaf, pork chops, or a simple pan-fried steak. A crisp green salad or steamed green beans balance the richness nicely, and a spoonful of these potatoes tucked into a leftover roast beef sandwich the next day is a little treat in itself. If you like, set a small bowl of sour cream or plain yogurt on the table for dolloping, but they’re flavorful enough to stand on their own.

Servings: 4

2 pounds small yellow or red potatoes, scrubbed and halved

Preheat your oven to 400°F (200°C). Line a 9x13-inch baking dish or a sturdy sheet pan with aluminum foil, letting the foil come up the sides to catch all the juices.

Place the halved potatoes in a large bowl. Add the sliced sweet onions on top.

Pour the melted butter over the potatoes and onions. Sprinkle with the kosher salt.

Using clean hands or a large spoon, toss everything together until the potatoes and onions are evenly coated and the salt is well distributed.

Spread the potatoes and onions out in an even layer in the foil-lined pan. Turn the potatoes cut-side down so they get nice and golden where they touch the pan.

Cover the pan loosely with another sheet of foil, crimping the edges just enough to trap some steam but not sealing it airtight. This helps the onions start to soften without drying out.

Bake covered for 25 minutes, then carefully remove the top foil (watch for steam). Stir the onions gently and flip a few potatoes if they seem pale, then spread everything back into a single layer, again aiming most potato halves cut-side down.

Return the pan to the oven, uncovered, and continue roasting for 25 to 35 minutes, stirring once or twice, until the potatoes are deeply golden and crisp on the edges and the onions are soft, browned, and caramelized. The onions should look deep golden and sticky in spots.

Taste and sprinkle with a little more salt if needed. Serve hot, right from the foil-lined pan, making sure each scoop has plenty of those sweet, caramelized onions mixed with the crispy potatoes.

For a little extra savoriness, you can add a small pinch of black pepper or garlic powder along with the salt, though my mother always insisted the four basic ingredients were all it really needed. If you prefer oil, you can swap half or all of the butter for olive oil; the butter gives a richer, more old-fashioned flavor, while oil makes the edges extra crisp. To stretch the recipe for a crowd, add another onion and a few more potatoes, but don’t crowd the pan too much or they’ll steam instead of brown—use two pans if needed. If your onions aren’t caramelizing, leave the pan in the oven for an extra 5 to 10 minutes, watching closely so they don’t burn. Leftovers reheat well in a hot skillet with a tiny dab of butter until crisp again, and they make a lovely base for a breakfast hash with a fried egg on top.