With a sharp knife, cut the sweet potatoes into long strips, about 1/4-inch wide, making sure they are all similar in size so they cook evenly.

Fill a large bowl with ice water and add the fries. Let soak for 30 minutes.

Preheat oven to 425 degrees F. Line 2 baking sheets with parchment paper and set aside.

Drain the fries in a colander. Rinse out the bowl and dry it. Put the sweet potatoes in the bowl and add the olive oil. Toss until well coated.

Sprinkle the cornstarch over the potatoes and toss until evenly coated.

Place the sweet potatoes in an even layer on the prepared baking sheets, making sure the potatoes aren’t touching.

Bake for 20 minutes. Remove the pans from the oven and flip the fries over with a spatula. Make sure they are still spaced out and not touching. Put the pans back in the oven, putting the pan you had on the bottom rack on the top this time to make sure they cook evenly.

Bake for 10 to 20 more minutes, or until crispy. I like my fries to get a little dark on the ends.

Remove the pans from the oven. Sprinkle generously with salt and a little pepper. Let cool for 5 minutes and serve warm.