Cut potatoes lengthwise into 3 thick slices. Then cut each slice into strips.
Bring a large pot of water to boil. Remove from heat. Place potato strips in hot water and allow it to soak for 10 to 20 minutes. Drain potatoes. Spread potatoes on layers of paper towels and pat dry with additional paper towels.
Wipe dry the empty pot. Toss potatoes in there with 2 tablespoon of vegetable oil.
Preheat oven to 450°F (230°C).
Coat a large baking tray with the remaining tablespoon of vegetable oil. Arrange potatoes on tray in a single layer. Place tray in oven and bake potatoes for 15 minutes.
Remove and flip potatoes with tongs keeping them in a single layer. Continue baking for another 15 minutes or until golden brown.
When finished baking, transfer fries to paper lined plate to blot out excess oil.