Place potatoes in a large saucepan; cover with water and add 1/2 teaspoon salt. Bring to a boil; reduce heat and simmer, uncovered, 20 minutes or until tender. Drain and place in a large serving bowl. Cool at room temperature at least 20 minutes.
Combine mayonnaise, remaining salt, green onions, and next 4 ingredients. Spoon over potatoes; toss gently to coat.