Refrigerate fish fillets while making stock. Combine all stock ingredients; bring to a boil. Lower heat and simmer 30 minutes. Strain and reserve. To make soup, cook, covered over low heat for 5 minutes, the butter, onion, carrot, leek, celery and garlic. Stir flour into vegetables; blend well. Add tomato paste and tomatoes, stirring until well mixed. Add mace or nutmeg and parsley; cover and cook over low heat 10-15 minutes. Add strained stock and fish pieces to vegetables. Bring to a boil, then simmer for 10 minutes. Add shrimp and simmer until heated through. Serve sprinkled with paprika.