Preheat the oven to 450°F.
In a small saucepan, combine the oil and garlic. Bring to a boil then turn off the heat and let cool for 5-10 minutes.
On a baking sheet, toss the potatoes with the garlic oil, salt and pepper. Spread out evenly and roast for 35-40 minutes, or until nicely browned and cooked through.
Whisk together the mayo and truffle oil in a small bowl. Season to taste.
Remove the potatoes from the oven and toss with parsley. Serve with truffle aioli.