Step 1

Preheat the oven to 425 degrees F and line a sheet pan with parchment paper.

Step 2

Add the sliced potatoes and onions to a large bowl. Drizzle with olive oil, then sprinkle with salt, pepper and rosemary. Toss until the potatoes and onions are all evenly coated.

Step 3

Spread the potatoes and onions out on the sheet pan in a single layer.

Step 4

Bake for 20 minutes, then use a spatula to toss the potatoes and onions around and flip some of them over. This doesn't have to be perfect, just make sure you move them around a bit.

Step 5

Bake for another 15-20 minutes or until the potatoes are golden brown and crisp in spots. Serve immediately.