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.