In a small saucepan, cover potato with water. Bring to boiling; reduce heat. Simmer for 10 to 12 minutes or until potato is very tender; drain. Set aside. Halve eggs and remove yolks. Set whites aside.
In a medium bowl, combine the cooked potato, egg yolks, mayonnaise, and lemon juice. Mash with a fork until well mixed. Stir in salmon, green onion, salt, and white pepper.
Spoon potato mixture into the egg white halves, mounding slightly. Cover and chill in the refrigerator for at least 2 hours or up to 24 hours. Makes 12 appetizer servings.