Nutrition per serving may change if servings are adjusted.
1/2 cup sundried tomatoes, (not packed in oil)
1 tablespoon extra-virgin olive oil
2 onions, coarsely chopped (about 2 cups)
1 medium or 2 small fennel bulbs, trimmed, cored and coarsely chopped (1 1/2 cups)
2 cloves garlic, minced
2 pounds fresh plum tomatoes, cored, halved, seeded and coarsely chopped, or two 28-ounce cans tomatoes, drained and coarsely chopped
1/2 cup chopped fresh parsley
1/2 teaspoon crushed red pepper
1 cup bottled clam juice, (see Tip)
1 cup dry white wine
12 ounces medium shrimp, in shells
24 small clams, such as littlenecks, scrubbed (about 3 pounds)
24 mussels, scrubbed and debearded (about 1 1/2 pounds; see Tip)
8 ounces cleaned calamari, thinly sliced (see Note)
1/2 cup plus 2 tablespoons chopped fresh basil, divided
2 tablespoons anise-flavored liqueur
Salt & freshly ground pepper, to taste
1 pound fresh spinach- or egg-pasta sheets, or 12 ounces dried lasagna noodles
2 tablespoons freshly grated Parmesan cheese
Sprigs of basil, or Italian parsley for garnish
Cover sundried tomatoes with boiling water in a small bowl and let stand until softened, about 10 minutes. Drain and cut into slivers.
Heat oil in a very large skillet or Dutch oven over medium-low heat. Add onions and fennel and cook until softened, about 5 minutes. Add garlic and cook for 1 minute. Increase heat to medium and stir in fresh (or canned) tomatoes, parsley, crushed red pepper and the slivered sundried tomatoes. Simmer, stirring often, until the juices are nearly evaporated, 15 to 20 minutes.
Meanwhile, bring clam juice and wine to a boil in a large pot over high heat. Add shrimp, lower heat and simmer, covered, until the shrimp are pink and just cooked through, about 2 minutes. Transfer to a bowl with a slotted spoon and set aside.
Add clams to the pot, cover and steam about 5 minutes, removing the clams as they open with a slotted spoon. Transfer to the bowl with the shrimp. Then add mussels to the pot. Cover and steam about 3 minutes, removing the mussels as they open with a slotted spoon. Transfer to the bowl with the reserved clams and shrimp. (Discard any clams or mussels that do not open.)
Strain the shellfish steaming liquid through a sieve lined with cheesecloth and measure out 1 1/2 cups. (Reserve any extra for another use.) Peel and devein the shrimp. Set aside 8 shrimp, along with 8 clams and 8 mussels in their shells, for garnish; cover and refrigerate. Cut the remaining shrimp in half lengthwise. Remove the remaining clams and mussels from their shells. Pull off the dark rubbery rim from the mussels.
Add calamari and the reserved 1 1/2 cups shellfish steaming liquid to the tomato sauce. Simmer until the calamari is cooked through, about 4 minutes. Remove from the heat and stir in the shelled clams and mussels, shrimp, 1/2 cup chopped basil and anise-flavored liqueur. Taste and season with salt and pepper.
Bring a large pot of salted water to a boil. Place a large bowl of cold water near the stove and lay some kitchen towels on the work surface. Cook pasta in boiling water, a few sheets at a time, until barely tender, 1 to 2 minutes for fresh pasta or 8 to 10 minutes for dried. Remove the pasta with a slotted spoon and drop it into cold water. Spread the pasta on the kitchen towels.
Lightly coat a 9-by-13-inch lasagna pan or 8 individual gratin dishes with cooking spray. Moisten the bottom of the pan (or dishes) with a spoonful of the tomato-shellfish sauce. Add a layer of pasta, using about 1/3 of the sheets, cutting to fit if necessary. Then spoon on half of the tomato-shellfish sauce. Make another layer with half of the remaining pasta, then add the rest of the tomato-shellfish sauce. Top with remaining pasta sheets.
Preheat the oven to 450 °F.
Sprinkle the lasagna with cheese. Bake until the tip of a sharp knife or skewer inserted in the center is hot to the touch, 10 to 20 minutes. Place the shrimp and shellfish that have been reserved for garnish decoratively on top and heat until they are warm, another 2 to 3 minutes. Remove from the oven and sprinkle with the remaining 2 tablespoons chopped basil. If baking lasagna in a large pan, let it stand for 5 minutes before cutting into squares, spooning any juices left in the baking dish over each serving. (Lasagna will be juicy.) Garnish with the basil or parsley sprigs.
Make Ahead Tip: Cover and refrigerate the sauce (Steps 1-6) for up to 1 day. The lasagna can be prepared ahead through Step 8; cover and refrigerate for up to 8 hours.
Tips: Bottled clam juice can be very high in sodium. We like Bar Harbor brand, which has 120 mg sodium per serving. Look for it in the canned-fish section or the seafood department of your supermarket.
Use a stiff brush to scrub mussels under running water. Discard any with broken shells or any whose shells remain open after you tap them lightly. Scrape off any barnacles; pull off the black fibrous “beard”.
Note: Calamari, also known as squid, is sold frozen or fresh in the seafood department of the grocery store. Look for cleaned calamari, with its cartilage and ink removed; otherwise ask at the fish counter to have it cleaned.