Place the egg yolks in the bowl of the food processor and add the vinegar and mustard. Season with salt, to taste. Turn the machine on and VERY slowly start to drizzle in the oil. Drip, drip, drip until the mixture starts to look like mayonnaise, then a slow steady stream of oil can be added.
Contains Raw Eggs: The Food Network Kitchen suggest caution in consuming raw and lightly cooked eggs due to the slight risk of salmonella or other food-borne illness. To reduce this risk, we recommend you use only fresh, properly refrigerated, clean grade A or AA eggs with intact shells, and avoid contact between the yolks or whites and the shell. For recipes that call for eggs that are raw or undercooked when the dish is served, use shell eggs that have been treated to destroy salmonella, by pasteurization or another approved method.
If the mayonnaise is too thick add a few drops of water or if it is not thick enough, with the machine running, add a little more oil.