4 (4 to 5-inches long) russet potatoes (1kg)
1 tbsp fine-grain sea salt
1 tsp freshly ground black pepper.
Wash potatoes but leave the skin on. Cut the potatoes into 1/3-inch slices and then slice into 1/3-inch sticks.
Fill a large bowl with water and soak potatoes, submerged, for at least 30 minutes up to 24 hours. This will help remove the excess starch from the potatoes and keep them from oxidizing.
Remove potatoes from the water, and pat dry to remove excess water.
Heat oil in deep-fryer to 325F/150C. Working in batches, par-cook until potatoes are light brown, 6 to 8 minutes. Remove potatoes, gently shaking off excess oil and let drain on rack. Repeat until all of the potatoes are par cooked.
Raise heat of oil to 350F/180C.
Working in batches fry potatoes again until golden brown, about 2 minutes. Remove from oil, shake off excess oil, and season lightly in a bowl with salt and pepper. Repeat until all potatoes are cooked.