Prepare the Potatoes: Wash the potatoes thoroughly, scrubbing away any dirt. You can peel them if you prefer a smoother chip, but I love leaving the skin on for extra texture and nutrients. Using a mandoline slicer, carefully slice the potatoes into uniform 1.5-2mm thick rounds. This uniform thickness is absolutely crucial for even cooking and consistent crispiness. You'll notice the slices are almost translucent when held up to the light.

The Essential Soak: Place the sliced potatoes into a large bowl and cover them completely with cold water. Add about a cup of ice cubes to ensure the water is very cold. Let them soak for at least 30 minutes, or even up to an hour. This step removes excess starch, which is key to preventing them from sticking together and achieving that ultimate crunch. You'll see the water becoming cloudy as the starch leaches out.

Dry Thoroughly: Drain the potatoes completely. This is perhaps the most critical step for crispiness! Lay the potato slices in a single layer on clean kitchen towels or paper towels. Gently pat them until they are as dry as possible. Any residual moisture will steam the chips instead of frying them, resulting in a soggy texture. They should feel almost completely dry to the touch before moving on.

Season and Coat: Transfer the dried potato slices to a large, clean bowl. Drizzle with the olive oil, then sprinkle over the salt, black pepper, smoked paprika, garlic powder, and onion powder (and cayenne pepper if using). Toss everything gently with your hands or a spatula until every single potato slice is lightly and evenly coated. They should look slightly glossy and uniformly spiced.

Preheat and Arrange: Preheat your air fryer to 180°C (350°F) for about 5 minutes. This ensures the air fryer is at the optimal temperature from the start, promoting immediate crisping. Arrange a single layer of potato slices in the air fryer basket, ensuring they don't overlap. Overcrowding will lead to steaming and uneven cooking, so work in batches. You should be able to see space between each chip.

Air Fry to Crispy Perfection: Air fry for 15-25 minutes, shaking the basket every 5-7 minutes to ensure even cooking and browning. Keep a close eye on them towards the end, as they can go from perfectly crisp to burnt very quickly. The chips are done when they turn a beautiful golden-brown colour, feel firm and brittle to the touch, and make a satisfying rustling sound when shaken. The smell of roasted potatoes and spices will fill your kitchen.

Repeat and Serve: Remove the crispy chips from the air fryer and place them on a serving platter or a wire rack to cool slightly. Repeat the process with the remaining potato slices, ensuring you maintain a single layer in the basket for each batch. Garnish with fresh parsley or chives if desired. Serve immediately and enjoy that incredible crunch!