Make the mayonnaise by whisking together all the ingredients until fully incorporated. Transfer to a small serving bowl and serve as a side with the fried potatoes.
Heat the oil over high heat in a large, heavy pot, such as a Dutch oven, until it reaches 375 degrees F. Carefully drop half of the potatoes into the hot oil and cook until nicely golden brown, about 8 minutes. Remove potatoes with a slotted metal spoon onto a plate lined with a double layer of paper towels. Season generously with salt and sprinkle with parsley. Serve the first batch and repeat the frying process for the second batch.
Recipe courtesy of Dave Lieberman