Set a pot of water to boil over medium-high heat. Preheat your oven to 475° F/246° C.

Meanwhile, peel the sweet potatoes and cut them into approximately 1/3 inch slices, then into roughly 1/3 inch thick fries.

When the water boils, stir in the vinegar and a sizeable pinch of salt until the salt dissolves. Add the sweet potato fries to the boiling water and boil them for 6 minutes.

Afterward, drain the fries using a colander. Gently scratch the surface of the fries with a fork to allow the upcoming slurry mixture to penetrate the crevices.

• Note: The vinegar slows the breakdown of the pectin, making the fries more durable. It does not significantly influence the flavor.

Combine the cornstarch and cold water in a bowl. Stir until it's fully mixed with no lumps. Add the hot, drained fries to the bowl and toss until the fries are coated with the thickened slurry. If needed, add more cornstarch to ensure a light coating.

Use tongs to transfer the fries to a wire rack placed over a large baking sheet. Ensure the fries are evenly spaced and not touching.

Drizzle the cooking oil over the fries using a squirt bottle or spoon, aiming for an even coating on each one.

• You can also use baking spray here.

Once prepared, add the sweet potatoes to the preheated oven and set a timer for 15 minutes to roast.

Remove the baking sheet from the oven and flip the fries using a spatula. You should notice some blistering on the surface, but the fries should not be overly crisp.

• If they appear dry, add more oil. Return them to the oven and continue roasting for an additional 10 to 15 minutes.

By now, the fries should be slightly browned and crispy. However, this could take longer depending on the size of the fries, the amount on the pan, or the type of oil used. If they are not crispy enough, continue baking for a longer duration!

Pour the fries into a bowl. Immediately add a pinch of salt and a few cranks of black pepper. Toss the fries in the seasoning and enjoy with your choice of dipping sauce.

• Note: Feel free to add spices, fresh herbs, cheeses, or any other flavorings of your choice at this stage.