Heat olive oil in large saucepan over medium heat; stir in onion, green pepper, carrot, celery and garlic. Cook, stirring occasionally, until vegetables are tender. Stir in tomatoes, broth, tomato paste and sugar; reduce heat to low. Simmer about 10 minutes, or until flavors are blended.
Add smoked whitefish and sherry. Continue cooking until heated through. Season with hot pepper sauce and additional sherry, if desired.