Heat the olive oil in a heavy bottom pot and add onion and peppers. Add a pinch of salt and cook until a light brown colour.Add garlic and stir for 2 minutes, then add diced tomatoes and white wine (if using). Bring to a simmer, add the fish stock.Bring back to a slow boil and add paprika(s). Add potatoes and continue cooking at a simmer for 20 minutes. Season with salt and pepper.When potatoes are cooked through, add diced fish and simmer as further 10 minutes or until fish is just cooked. Taste and adjust salt and pepper.Ladle soup into bowls and garnish with fresh parsley and a dollop of sour cream. Serve with warmed bread rolls.