Cioppino with Mussels

Ingredients

• 3 tablespoons extra-virgin olive oil
• 1 large shallot, minced
• 6 garlic cloves, halved
• 1/3 cup loosely packed basil leaves, torn
• 4 pints cherry tomatoes (about 2 pounds), halved
• 1 1/2 cups dry white wine
• Three 14.5-ounce cans whole tomatoes
• Salt
• 1/4 cup extra-virgin olive oil
• 1 leek, white and light green parts only, halved lengthwise and thinly sliced crosswise
• 1/2 fennel bulb, finely chopped
• 1/2 cup thinly sliced young celery leaves
• 4 oregano sprigs
• 1/2 teaspoon crushed red pepper
• 1 pound littleneck clams, scrubbed
• 2 pounds mussels, scrubbed
• 1 pound large shrimp, shelled and deveined
• Four 3-ounce skinless red snapper fillets
• Flat-leaf parsley leaves, for garnish
• Toasted baguette slices, for serving