Wash and peel 3 medium russet potatoes (about 1½–2 lb). Using a mandoline set to a 1/8-inch (3 mm) slice or a sharp knife, slice the potatoes into thin, even rounds. You should end up with about 4 cups of sliced potatoes.

Rinse and soak

Place the potato slices in a large bowl and cover with cold water. Add 2 tablespoons white vinegar to help keep the slices from discoloring and to slightly firm the starches. Gently agitate, then drain and refill with fresh cold water. Let soak for 20–30 minutes to remove excess surface starch (this helps chips crisp).

Dry and season

Drain the potatoes and spread them on clean kitchen towels or paper towels. Pat thoroughly dry — moisture will cause oil splatter and reduce crispness. In a small bowl combine 1 tablespoon kosher salt, 1 teaspoon black pepper, 1 teaspoon smoked paprika, 1 teaspoon garlic powder, and 1 teaspoon onion powder. Set seasoning aside.

Frying & Finish

Heat oil

In a heavy-bottomed pot or Dutch oven, pour in about 6 cups neutral oil (enough for 2–3 inches depth). Attach a deep-fry or candy thermometer and heat oil to 325°F (163°C) for the first blanch fry. Maintain steady temperature: do not exceed 350°F.

First fry (blanch)

Working in small batches (do not overcrowd), gently add a single layer of potato slices to the hot oil using a spider or slotted spoon. Fry for 2–3 minutes until the slices are softened and very pale — they should not brown. Remove with a slotted spoon and drain on a wire rack or paper towels. Repeat with remaining slices.

Increase heat

Raise oil temperature to 375°F (190°C) for the crisping fry. Allow oil to come back to temperature between batches.

Second fry (crisp)

Fry the blanched potato slices in batches at 375°F for 1–2 minutes, turning as needed, until golden brown and crisp. Monitor closely — chips brown quickly at this temperature. Remove with a slotted spoon and drain on a wire rack or paper towels. Immediately while still hot, sprinkle each batch lightly with the prepared seasoning mix and a pinch of flaky finishing salt.

Cool and finish

Let chips cool completely for a few minutes to set crispness. If desired, toss lightly with 1 tablespoon finely chopped fresh parsley for color and a fresh note. Taste and adjust seasoning, adding more flaky salt if needed.

Storage

Once fully cooled, store chips in an airtight container at room temperature for up to 2 days for best crispness. Recrisp briefly in a 300°F (150°C) oven for 3–5 minutes if they soften.