Whiz all the ingredients except the oil in a food processor on a low speed for 30 seconds. With the motor running (still on low), very slowly drizzle in the oil until the mayo is thick and smooth. (Did I mention to drizzle it very slowly? You want it to pour in a very, very fine stream, otherwise it won’t form an emulsion.) If you included the whey, cover the mayonnaise and let it sit at room temperature for 8 hours before refrigerating. This activates the enzymes in the whey. If you didn’t use whey, refrigerate immediately.