Prepare the sweet potato: Cut off either end and cut the sweet potato into long ¼ inch thick spears. Ideally you want them evenly sized. If any are smaller I recommend setting them aside on a separate baking pan so you can pull them out early so they do not burn. I also recommend squaring off the pointy tips otherwise you will get burnt tips.Ice, ice baby! Fill a large mixing bowl with cold water and two handfuls of ice cubes. Add the raw sweet potato fries, stir and allow them to soak for 30 minutes minimum or an hour if you have time. I like to soak overnight for best results. When finished soaking, preheat your oven to 415 degrees Fahrenheit on the convection setting. Drain the water from the soaked sweet potato fries, rinse with fresh water and pat them dry with a kitchen towel. You want to remove all excess moisture so they are completely dry when they go into the oven.Season: In a large bowl, toss the dry sweet potato spears with arrowroot starch and pepper using two large spoons. Add any other seasonings you wish to use at this time (just not the salt). Toss well with two spoons to evenly coat. Next, add the oil and toss again using the spoons until you cannot see the arrowroot powder. Place the spears on two half sheet baking pans lined with either parchment paper or silicone baking mats. You can also use a cast-iron skillet or place an oven safe wire cooking rack on the baking sheet (see Tip #8 for more information this).Cook the fries: Evenly space out the sweet potato spears on the two baking sheets so they are not touching or they will steam. Place the baking sheets in the middle and lower position in the oven and bake at 415 degrees Fahrenheit on the convection setting for 15 minutes. At the 15 minute mark, remove the baking sheets from the oven and carefully flip each spear 180 degrees using two forks. Place the sheet pans back in the oven and switch their placement (the middle pan should now go on the bottom rack). Bake for 10-13 minutes watching closely at the end to avoid burning. They are done when the majority of the fries are golden brown. Cooking time varies slightly based on the thickness of your spears so watch carefully at the end.Salt & Wait: When the fries are done cooking, remove them from the oven and wait five minutes. Season with salt and wait another 5 minutes. Waiting the full ten minutes allows them to crisp up even more so try and resist eating right away. Enjoy immediately as they are best when fresh.