Step 1 In the bowl of a food processor or blender, combine the egg yolk, lemon juice, salt, mustard and chopped chiles, processing to combine. With the processor running, slowly drizzle in the oil to emulsify; if using a processer, scrape down the bowl once or twice to make sure all of the oil is incorporated and the ingredients are fully combined. This makes a generous cup of aioli. The aioli will keep, covered and refrigerated, for up to 1 week.