In the bowl of a food processor, combine the egg, vinegar, and mustard, and process on high speed for 30 seconds. With the machine running, add the oil through the feed tube and process until it forms a thick emulsion. Add the peppercorns and pulse until well blended. Adjust seasoning, to taste. Transfer to a decorative bowl and serve with the Blue Cheese-stuffed Hamburgers.

*RAW EGG WARNING The American Egg Board states: "There have been warnings against consuming raw or lightly cooked eggs on the grounds that the egg may be contaminated with Salmonella, a bacteria responsible for a type of foodborne illness.Ö Healthy people need to remember that there is a very small risk and treat eggs and other raw animal foods accordingly. Use only properly refrigerated, clean, sound-shelled, fresh, grade AA or A eggs. Avoid mixing yolks and whites with the shellÖ"