Serves 6.
1 large egg yolk, at room temperature
1 Tbsp white wine vinegar or lemon juice
2 large garlic cloves, peeled
5 Tbsp extra virgin olive oil
5 Tbsp canola or vegetable oil
Kosher salt and fresh black pepper
1 lb red-skinned potatoes
1 Tbsp roughly chopped flat-leaf parsley
Make the aioli: Add the egg yolk, vinegar and garlic to a food processor fitted with the metal blade. With the motor running, add olive oil drop by drop, and then the canola oil drop by drop. When the mixture starts to thicken, add the remaining oil in a steady stream, until it looks like a yellow-ish mayonnaise. Season with salt and pepper to taste. (Can be made ahead and refrigerated for several hours. Bring to room temperature before using; cold mayonnaise will not absorb easily into warm potatoes.)
Cut the potatoes into bite-size pieces, and place in a sauce pan with cold water to cover. Bring to a boil over high heat, then lower the heat to simmer and cook for 7 minutes, or until just tender. Drain well, then add to a large bowl. Stir in the aioli dressing, and mix gently to combine. Let sit for 15-20 minutes, to allow the potatoes to absorb some of the sauce. Garnish with parsley, season with salt if needed, and serve warm or at room temperature.