Combine egg, lemon juice, mustard, salt and white pepper in a blender
container or food processor bowl. Cover and blend at low speed until
mixed. Increase speed to high; uncover and remove center cap.
Add oil in a thin, slow, steady stream. Blend until all oil is added
and mayonnaise is smooth and creamy. If necessary, turn motor off
and stir occasionally. Replace cover before turning motor back on.
Keep mayonnaise refrigerated, and use within 7 to 10 days.