Linguine with Seafood

Name: Linguine with Seafood
Ingredients: 1 pound linguine; 2 tablespoons salt, plus 1 1/2 teaspoons; 6 tablespoons extra-virgin olive oil; 1 cup finely chopped yellow onion; 2 tablespoons thinly sliced garlic; 1/2 teaspoon Italian Essence; 1 teaspoon crushed red pepper flakes; 1 cup dry white wine; 2 tablespoons tomato paste; 1 (28-ounce) can crushed tomatoes; 1 pound rock shrimp, peeled and deveined; 1 pound small clams, such as littlenecks, or cockles, scrubbed and purged in salted water, any open or broken clams discarded; 1 pound mussels, scrubbed and debearded; 1/4 cup chopped fresh basil leaves; 2 tablespoons chopped fresh parsley leaves; 1/3 cup grated Parmesan