I usually find it easiest to buy Japanese mayonnaise, from either an Asian market or from Hughes Market supermarkets in the Southwest. It comes in a convenient plastic squeeze bottle. Several people have asked about a recipe for this mayonnaise, and I recently found the following one. It is available in Asian markets and some health food stores.
White miso is used for soups and dressings.
Kaffir lime used in Thai or Malaysian food is an alternative, as is lemon or lime rind. Beat the egg yolks and lemon juice with a wooden spoon in a bowl. Continue to beat, adding the salad oil a few drops at a time until the mixture begins to emulsify. Keep on adding the rest of the oil, then stir in the miso and the seasonings. Refrigerate in a squeeze bottle.