In a large skillet, combine the water, wine, onions and peppercorns. Bring to a boil. Reduce heat; carefully add salmon. Cover and cook for 5-7 minutes or until fish flakes easily with a fork., With a spatula, carefully remove salmon; discard cooking liquid. Cool salmon for 10 minutes; refrigerate until chilled. In a small bowl, combine the sauce ingredients. Serve with salmon.