1. Combine cucumber and salt in a large bowl. Let stand 30 minutes.
2. Cook potatoes in boiling water 20 minutes or until just tender; drain. Combine potatoes, broth, and wine in a bowl. Let stand 5 minutes. Add potato mixture to cucumber mixture.
3. Combine Champagne vinegar and the next 4 ingredients (through nutmeg) in a small bowl; stir with a whisk until blended. Add vinegar mixture, onions, parsley, and chives to the potato mixture; toss well to coat.