Add the olive oil and garlic cloves to a small saucepan. Simmer on low until the garlic is golden brown and fork tender, about 30 minutes.
Strain the garlic cloves out and reserve the oil.
Garlic aioli
In a small food processor, combine the mayonnaise, roasted garlic, lemon juice, salt, and pepper. Blend until smooth. Transfer to a serving bowl.
French fries
Preheat the oven according to the package directions.
Put the french fries in a large zipper top bag. Add 2 tablespoons of the reserved garlic oil, seal the bag, and toss to coat the fries evenly.
Add the seasonings to the bag. Seal and toss to evenly distribute the spices.
Transfer the fries to a parchment-lined sheet pan. Bake according to package directions, flipping the fries halfway through.
Serve immediately with garlic aioli.
Notes
Reserve the extra garlic oil to use in dressings or sauces or toss with pasta or roasted vegetables.
For best results, cook the frozen french fries according to the package directions.
The optimal baking temperature is 425-450 degrees. Baking at a temperature below 400 degrees will likely cause the fries to steam, which means soggy fries.
For the optimal crisp texture, take care to avoid overcrowding the pan. Spread the fries in an even layer and flip them halfway through the baking time.