How do I cut potatoes into an accordion shape?
Place a potato between two wooden spoons or chopsticks to limit knife depth. Slice crosswise at 1/4-inch intervals, stopping before you cut all the way through. The spoons prevent the knife from cutting the base.
Why should I soak the potatoes in water first?
Soaking removes excess starch, which helps the potatoes crisp better during roasting and prevents them from sticking together.
Can I make these ahead of time?
Slice and soak potatoes up to 4 hours ahead. Assemble and bake just before serving for best crispiness; reheating makes them soft.
What potato variety works best?
Russet potatoes are ideal for their starch content and size. Avoid waxy potatoes like red or fingerlings, which don't crisp as well.
How do I know when they're done?
Potatoes are ready when the exterior edges are deep golden brown and a fork pierces the thickest part easily, typically 35–45 minutes at 400°F.