Pre-heat the oven to 225°C/ 435°F and line a baking sheet with parchment.
Wash 2 sweet potatoes and peel them if you like, before cutting them into 50x50mm - 0.2"x0.2" fries. The more evenly you cut them, the more even they will cook. So try and be tidy (or not).
Place the fries into a bowl of cold water and let them sit there while you mix your spices.
Mix a pinch of ground white pepper with a pinch of garlic powder and 2 T - 30 gr of corn starch. DO NOT ADD THE SALT.
Drain and roughly dry the fries with a tea towel.
Place the dried fries back into the dried bowl, drizzle with 2 T - 30 ml of oil and mix together so all the fries are coated evenly.
Sprinkle your fries with a thin layer of the cornstarch/ spice mix. Make sure the fries get evenly coated.
Place the fries on your baking sheet in a single layer. Make sure none of the fries are touching. Make sure your fries have breathing room or they won't crisp up.
Bake your fries in the oven for 30-45 minutes. Turn the fries every 10-15 minutes until they are crisp (or crisp enough, because well really now...). Remove smaller fries if they're done cooking sooner and have a little pre-nibble if you want.
Season your fries with salt.