Preheat your oven to 425°F (218°C). Arrange the frozen french fries in a single layer on a large baking sheet lined with parchment paper.
Bake the frozen fries for 20-25 minutes, shaking the pan halfway, until golden brown and crispy.
While the fries bake, grate the Parmesan cheese and chop the fresh parsley.
Remove the fries from the oven and transfer them to a large bowl. Drizzle with 2-3 tablespoons of truffle oil.
Using tongs or two spoons, gently toss the hot fries with the truffle oil until evenly coated. Season with salt to taste.
Transfer the truffle-tossed fries back to the baking sheet and spread into an even layer.
Sprinkle the freshly grated Parmesan and chopped parsley over the top. Return to the oven for 2-3 minutes until the cheese is melted.