Place cut fries in a large bowl and cover with cold water. Add ice cubes to keep water cold and soak for 30 minutes to 1 hour to remove excess starch. Drain and rinse under cold water until water runs clear.

Dry and toss with cornstarch

Thoroughly dry the potato sticks with clean kitchen towels or paper towels. Transfer to a bowl, sprinkle the cornstarch and 1 tsp salt over the fries, and toss gently until lightly coated.

First fry (blanch)

Heat the oil in a heavy pot or deep fryer to 325°F (160°C). Fry the fries in batches (do not overcrowd) for 3–4 minutes until soft and just beginning to color. Remove with a slotted spoon and drain on a wire rack or paper towels. Let cool for 10 minutes.

Second fry (crisp)

Increase oil temperature to 375°F (190°C). Fry the blanched fries in batches for 2–3 minutes or until golden brown and crisp. Drain on a wire rack or paper towels and immediately sprinkle with a pinch of flaky sea salt to help salt adhere.

Truffle Finish

Prepare truffle butter/oil

In a small saucepan over low heat, melt the unsalted butter with the extra-virgin olive oil—just until melted; do not brown. Remove from heat and stir in the truffle oil. This mixture will evenly coat the fries with truffle flavor.

Toss fries with truffle mixture

Place the hot, drained fries in a large mixing bowl. Pour the warm truffle butter and oil mixture over the fries, then gently toss to coat every fry evenly. The heat will help the oil and butter adhere.

Add cheese and seasonings

While fries are still hot, sprinkle the grated Parmesan, finely chopped parsley, and freshly ground black pepper over them. Toss gently so the cheese melts slightly and clings to the fries.

Finish and serve

Transfer fries to a serving platter. Taste and adjust seasoning with flaky sea salt as needed. If using, scatter shaved fresh black truffle over the top for an elevated presentation. Serve immediately while hot and crisp.