Sprinkle roughy fillets with white wine vinegar, garlic powder, dill weed and crushed red pepper. Marinate about 15 minutes - melt oil and butter over heat. Braise fillets about 1 minute each side over high heat - lower to medium heat and cover. Heat about 6 minutes for 4 fillets - add heavy cream and heat through. Serve warm.
Do not over cook - heat fillets only until they flake and are pure white color. Serve with garden salad, baked potatoes and cooked broccoli spears.