- In a large and heavy pot, soften the onion and garlic in the oil. Add the broth, tomatoes, and beans. Bring to a boil and simmer for about 10 minutes or until the vegetables are al dente. Add the zucchini and bring to boil. Cook for about 5 minutes. Add the shrimp and cook for about 1 minute or until cooked.
- Meanwhile, in a large pot, bring the clams and wine to a boil. Cover and cook for about 3 minutes. Add the mussels. Cover and continue cooking, stirring frequently until they open, from 4 to 5 minutes. Discard any unopened mussels and clams. Drain. Strain and pour the cooking juices into the soup.
- Keep about 18 mussels and the clams in their shells. Peel the remaining mussels and add them to the soup.
- Ladle the soup into four to six bowls. Garnish with the mussels and clams in their shells. Garnish with basil leaves, if desired. Serve with toasted country bread.