Heat oven to 375°F. Pierce potato several times with fork to allow steam to escape. Microwave uncovered on High 5 to 6 minutes or until tender. Cool slightly, about 5 minutes. Cut in half lengthwise; scoop out inside into small bowl. Mash with fork. Stir in lemon peel.
Separate dough into 8 biscuits. Press or roll each to form 6-inch round. Place on ungreased cookie sheet. Place 1 piece salmon on half of each dough round. Spoon about 2 tablespoons potato mixture over salmon on each round, to within 1/2 inch of edge. Sprinkle each with 1 1/2 teaspoons green onion. Fold dough in half over filling; press with fork to seal.
Bake 15 to 18 minutes or until golden brown.