Preheat oven to 425 or deep fryer to highest setting
Peel sweet potatoes, slice into medium thick slices (closer to thin than thick).
Soak potatoes at least 4 hours in water.
Drain water from sweet potatoes and shake dry with your hands.
Put 1 Tablespoon of cornstarch into food safe plastic bag.
Dump sweet potato fries into bag, blow some air into it, and shake bag until fries are coated.
Place fries on cookie sheet, drizzle with a couple Tablespoons of olive oil.
Toss fries until evenly coated with oil.
Arrange on cookie sheet(s) with lots of space in between fries to prevent steaming.
Cook in hot oven for 15 minutes then check.
The fries will release from the pan when they're ready to flip the same way a steak would.
Flip fries, and continue to cook for another 5-10 minutes.
(cooking time depends greatly on the quality of your baking sheet so keep an eye on them)
Dipping Sauce: Mix together mayo, pepper and Sriracha sauce. Adjust to your taste.