Pat salmon steaks dry and sprinkle with salt and pepper.
Melt butter in a large skillet and saute salmon over medium heat about 5 minutes, turn over and cook another 5 minutes or until cooked though and flakes easily with a fork.
Transfer to a plate and cover with foil to keep warm.
Stir vinegar into skillet and cook until liquid is reduced to about 1 Tablespoon, scraping up brown bits.
Add mustard, sugar, whipping cream, salt & pepper and mix well. Cook until heated through.
Pour over salmon steaks and serve immediately.
Nutrition Info Per Serving: Calories 519.9 Total Fat 38.8 g Saturated Fat 19.2 g Polyunsaturated Fat 5.4 g Monounsaturated Fat 11.4 g Cholesterol 186.1 mg Sodium 532.7 mg Potassium 868.9 mg Total Carbohydrate 2.4 g Dietary Fiber 0.0 g Sugars 2.4 g Protein 34.8 g