Preheat the oven to 425 degrees.: Warmth fills the kitchen and you will notice a faint dry, warm aroma as the oven reaches temperature. Starting with a properly preheated oven ensures even, steady heat for browning, which is essential to develop that crisp exterior. A common mistake is under preheating, which leads to limp, steamed potatoes rather than roasted ones. If your oven runs hot or cool, adjust slightly and use an oven thermometer so you get the right caramelization.
In a large 15-inch cast iron skillet, toss the potato with the remaining ingredients until well combined. Arrange in an even layer, with as little overlap as possible. Bake in the middle of the oven for 20 minutes until the bottom of the potatoes is just starting to brown.: As you mix, the olive oil should give the cubes a glossy sheen, and the spices will cling to the surface. This step primes the potatoes for even browning; the oil conducts heat while the paprika and herbs de Provence begin to roast and bloom. Avoid overcrowding when tossing because crowded pieces will steam instead of crisping. If you notice pools of oil, blot or reduce slightly to avoid greasy results.
Remove the pan from the oven and using a sturdy flat metal spatula, redistribute the potatoes. If little pieces get stuck on the bottom of the pan, don’t worry. They’ll just become all the more crispy and delicious. Arrange in an even layer, and return to the oven. Bake for another 15 to 20 minutes, until the potatoes are very crispy on the outside and tender on the inside.: You want clear contact with the hot pan and hot air, so spread the cubes so each one touches the surface or has space around it. The surface contact encourages Maillard reactions that give you savory brown edges and a nutty aroma. A trap is piling the potatoes; if they overlap significantly, flip them halfway through to compensate and separate stuck pieces gently.
Serve the potatoes alongside eggs or savory crepes. They taste great with aioli, romesco, or a spicy pesto on the side.: During this time you will hear a quiet stillness, then start to pick up soft sizzling and the smell of nutty roasted potato. The initial bake sets and seals edges, creating the foundation for the final crisp. Underbaking here means the potatoes will not achieve that deep crust later. Check visually for the first signs of golden brown at the edges as your guide.
Remove the pan from the oven and using a sturdy flat metal spatula, redistribute the potatoes.: At this stage, you should see browned undersides and a rich roasted scent. Redistributing encourages even browning on all sides and helps loose bits become extra crispy. If small pieces are stuck, leave them; they will caramelize further and add texture. Avoid scraping too aggressively which can tear the cubes and create mushy pieces.
If little pieces get stuck on the bottom of the pan, don’t worry.: Those stuck fragments will crisp up and become intensely flavorful, adding textural contrast. They darken quickly, so keep an eye to avoid burning which can introduce bitterness. If you prefer cleaner pan surfaces, loosen them gently with a spatula after the pan cools slightly, but I usually embrace them for the added crunch.
Arrange in an even layer, and return to the oven.: Re-spacing the cubes at this point allows hot air to circulate and finish the browning. You should notice an intensified roasted aroma and a richer color developing in the oven. Crowding now will halt the final crisping, so take a moment to make the layer even. If you see uneven color early, rotate the pan for more uniform results.
Bake for another 15 to 20 minutes, until the potatoes are very crispy on the outside and tender on the inside.: The final bake is where the contrast becomes obvious: crunchy, golden exteriors and soft, yielding centers. Listen for amplified sizzling, and watch for deep golden patches. Overbaking risks drying the interior, so test by piercing a cube to confirm tenderness. If you find some pieces too browned, remove them early to prevent a bitter finish.
Serve the potatoes alongside eggs or savory crepes.: Hot potatoes carry an inviting aroma and a warm texture that pairs beautifully with runny yolks or delicate crepes. Serving immediately preserves the crispness, and you will notice the butter like softness inside when cut. A frequent slip is letting them sit too long, which causes steam to soften the crust; serve right away for best texture.
They taste great with aioli, romesco, or a spicy pesto on the side.: These sauces add a bright or creamy counterpoint to the roasted potatoes, creating layers of flavor with every bite. The contrast between the crispy potatoes and a silky dip is especially satisfying and makes each forkful interesting. Avoid over saucing which can drown the crisp; offer dips on the side so each diner can choose.