These crispy oven roasted potatoes are golden and crunchy outside, fluffy inside, and they actually stay crispy on the plate. After 14 test batches, the method is simple: parboil, fluff the edges, skip the parchment, and roast at 425°F. No duck fat needed.
Preheat. Heat your oven to 425°F. Bring a large pot of water to a boil and add 1 teaspoon of salt (and ½ teaspoon baking soda, if using).
Cut and parboil. Cut the potatoes into 1-inch cubes. Add them to the boiling water and cook for 10 to 14 minutes, until fork-tender but not falling apart.
Drain and fluff. Drain the potatoes and return them to the pot (or place them in a colander). Shake gently for 10 to 15 seconds, until the edges look rough and fluffy. This is what makes them crispy.
Season. Transfer to a bare metal baking sheet (no parchment paper). Drizzle with the olive oil and sprinkle with the garlic powder, onion powder, paprika, salt, pepper, and rosemary, if using. Toss to coat evenly, then spread in a single layer with space between each piece.
Roast (first round). Roast for 20 minutes without touching them. Don't flip early, or the crust will tear off before it sets.
Flip and finish. Flip the potatoes with a spatula, then roast another 20 to 25 minutes, shaking the pan once or twice, until deep golden brown and crispy. Serve immediately.
Notes
Best potatoes: Baby Yukon Gold. Russets work if peeled and cut to 1½ inches. Skip baby reds.Skip the parchment: It traps steam and gives you soft bottoms.Baking soda (optional): Use ½ teaspoon, not baking powder, and no more, or they can taste soapy.Make-ahead: Parboil and season up to 4 hours ahead, then roast right before serving. They stay crunchy for about 30 minutes out of the oven, long enough to get dinner on the table.Storage and reheat: Up to 3 days in the fridge. Reheat in the air fryer or oven at 400°F, never the microwave.