Heat a large Dutch oven or heavy pot over medium-low heat. Add the shallots and fennel to the olive oil, sautéing for about 5 minutes until they soften and become fragrant.

Add the garlic to the pot and cook for an additional 2 minutes.

Sprinkle in the crushed red pepper flakes and sauté for 30 seconds.

Pour in the dry white wine, turning the heat to medium-high. Scrape the bottom of the pot to lift any brown bits, cooking the wine for 90 seconds.

Combine the pulsed or crushed tomatoes with the clam juice, and then reduce the heat to medium. Allow the sauce to simmer moderately for 10 minutes.

Incorporate the calamari into the simmering sauce, and cook for 15 minutes until tender.

Add the chunks of cod or your chosen white fish, cooking for an additional 5 minutes.

Introduce the cleaned little neck clams to the pot, covering it with a lid. Cook for 5-7 minutes, or until the clams just begin to open.

Stir in the mussels and shrimp, covering once more. Cook until the shrimp turn pink and the mussels open (about 5-7 minutes).

Discard any clams or mussels that remain closed after cooking.

Taste the broth and season with salt and pepper as needed. Turn off the heat and fold in the minced parsley. Serve warm.