Saute onion, pepper and garlic in the butter and oil in skillet, about 10 minutes. Sprinkle with paprika and mix well. Add tomatoes, 1 cup water, bay leaf, fines herbes and salt. Bring to a boil and simmer, uncovered 15 minutes or until sauce is slightly thickened. Add fish, cut in large pieces; cover and simmer 15 minutes longer, or until fish flakes easily with a fork. Add more salt if necessary. Sprinkle with parsley and serve with potatoes.