Makes 1 cup
large egg yolk, room temperature
salt, plus more to taste
lemon juice, plus more to taste
- Place the egg yolk and salt in a food processor. Pulse to combine. Add the lemon juice and mustard; blend well. With the motor running, add the oil, drop by drop. This will take a few minutes. Don't rush it or the mayonnaise may "break," meaning the oil will separate from the egg. (Note: If your food processor has a small hole in the feed-tube pusher, pour the oil in there and let it drip through.)
- Once you've added the oil, sample the mayo and add more salt or lemon juice to taste. Cover tightly and refrigerate for up to 5 days. Stir before spreading.