Poached Salmon with Dill-Mustard Sauce

Sauce: 
2 tablespoons reduced-fat sour cream 
1 tablespoon mayonnaise (salad dressing) 
1 1/2 teaspoons chopped fresh dill (I used dried dill)
1 1/2 teaspoons lemon juice 
1 1/2 teaspoons Dijon mustard

Salmon:
3 1/2 cups dry white wine
2 cups water 
1/4 cup lemon juice 
2 cups thinly sliced onion 
2 dill sprigs (again, I used dried) 
4 salmon fillets, skin on 

1. To prepare sauce: combine the first 5 ingredients in a small bowl, stirring well. Cover and chill 2 hours. (Can be made up to two days in advance.)

2. To prepare salmon, heat white wine, 2 cups water, fresh lemon juice, sliced onion, and two dill sprigs in a large skillet at 150 degrees. Cover and simmer 10 minutes. Add fish to wine mixture; cook at 150 degrees for 12 minutes or until desired degree of doneness. Top with sauce.