Preheat and Prepare: Place two large, heavy-duty baking trays into the oven and preheat it to 220°C (200°C fan). Getting the trays screaming hot before the fries hit them is a key step for an initial sear.

Cut the Fries: Wash and peel your sweet potatoes. Slice them into uniform batons about 1cm (a little less than ½ inch) thick. Try to keep them as consistent in size as possible to ensure they all cook evenly.

Soak the Potatoes: Place the cut sweet potato fries into a large bowl and cover them completely with cold water. Let them soak for at least 30 minutes, or up to an hour. This step removes excess starch, which helps them become much crispier. You'll see the water turn cloudy.

Dry Thoroughly: Drain the fries completely and tip them onto a clean tea towel or several sheets of kitchen paper. Pat them until they are as dry as you can possibly get them. Any lingering moisture is the enemy of crispiness!

Coat with Cornflour: Place the dry fries back into the (now dry) large bowl. Sprinkle the cornflour over them and toss very well until each fry is lightly and evenly coated in a thin, dusty layer.

Season the Fries: Drizzle the olive oil over the fries, then sprinkle on the smoked paprika, garlic powder, onion powder, salt, and pepper. Use your hands to toss everything together, ensuring every single fry is coated in the oil and spices.

Arrange on Trays: Carefully remove the hot trays from the oven. Working quickly, arrange the fries in a single layer on each tray. Do not overcrowd them! Leave space between each fry. What works best for me is using two trays to ensure none of the fries are touching; this allows hot air to circulate and roast them properly.

Bake to Perfection: Place the trays in the oven and bake for 15-20 minutes. After this time, use a spatula or tongs to carefully flip the fries over. Return to the oven and bake for another 10-15 minutes, or until they are golden brown and wonderfully crisp at the edges.

Serve Immediately: As soon as they're done, remove them from the oven. Taste one and sprinkle with a little extra sea salt if needed. Serve them hot for the best texture.