1-Prep the potatoes: Wash, peel, and cut Russet potatoes into 1/2-inch thick sticks. Soak in cold water for at least 30 minutes to remove excess starch.

2-Parboil: Drain the potatoes and boil with 1 tablespoon of vinegar for exactly 3 minutes, then drain and pat completely dry.

3-Make the batter: Whisk together flour, cornstarch, and 2 tablespoons Cajun seasoning, then slowly whisk in cold seltzer water until a thin, smooth batter forms.

4-First fry: Heat oil to 330°F; dip each potato stick in batter, let excess drip off, and fry in small batches for 4-5 minutes until lightly golden and tender. Transfer to a wire rack.

5-Freeze: Spread the parfried fries in a single layer on a baking sheet and freeze for 15 minutes to enhance crunch.

6-Second fry: Increase oil temperature to 375°F; add frozen fries in batches and fry for 3-4 minutes until deep golden brown and crispy. Drain on a wire rack.

7-Season and serve: While hot, toss the fries with additional Cajun seasoning to taste and serve immediately.