Start warming up the oil to fry by adding it to a large heavy pot or fryer to 375°F (you can test the oil by adding a french fry and if it immediately sizzles, it’s ready).
Make the pomme frites seasoning by mixing the garlic, cajun seasoning, Parmesan cheese, and parsley in large mixing bowl. Set aside.
In a medium bowl, make the batter by mixing the flour, water, garlic salt, and salt. This batter should be runny.
In batches, dip frozen french fries into the batter just to coat, letting excess run off.
Fry battered french fries until golden brown (about 4-5 minutes). Transfer french fries to a paper towel-lined plate for a few seconds and then toss in the cheese mixture and stir to coat.
Transfer fries to a serving dish lined with parchment paper and serve hot with remoulade.