Directions:
Put the egg, garlic, lemon juice, parsley, green onions, and relish in a food processor or blender and process for 15 seconds. With the motor running, pour the oil through the feed tube in a slow steady stream. Add the cayenne, mustard, and salt and pulse once or twice to blend.
Cover and let sit for 1 hour in the refrigerator before using. Best if used within 24 hours.