Wash and peel the sweet potatoes. Cut the sweet potato in half first. Then cut the halfs into 3 pieces if they're large and 2 pieces if they're small. But don't overcomplicate it either, just try your best to keep them all the same size.
Add the cornstarch and toss well.
Get 1-2 baking trays and line them with parchment paper. Add the oil and it spread across the two trays.
Line up the dusted sweet potato fries across the two trays.
Roast the sweet potatoes in the oven for 20 minutes. Then turn each wedge over on the tray and put back in the oven until nicely coloured and crispy. Approx. 15-20 minutes more.
Season the wedges generously with salt and serve right away!
Notes
Be careful not to burn yourself when removing the trays from the oven because of the hot oil. Serve right away as the crispiness does not last long.