5 pounds russet potatoes ▢vegetable or peanut oil, for frying ▢sea salt
Peel potatoes. Cut them into slices lengthwise then cut each slice into french fry-sized sticks. To remove excess starch, add the potatoes to a large bowl and cover with cold water, soak 2-3 hours, then pat dry with a clean kitchen towel.
When ready to cook, drain the water and lay the potatoes out on a baking sheet lined with paper towels. Blot with additional paper towels to dry.
Heat a few inches of oil in a heavy large pot to 300°F. Add the potato pieces in 3-4 batches so as not to crowd the pot. Cook 4-5 minutes. (The potatoes will still be pale and not fully cooked.)
Remove the potatoes from the pot with a slotted spoon and drain on fresh paper towels, then cook the remaining batches.
When all of the potatoes have been cooked at 300°F, turn the heat up to 400°F. Add the potatoes again in batches, cooking until golden brown and crisp. Drain the fries on paper towels. Sprinkle with sea salt. Serve immediately.