In a heavy pot, heat 2 tablespoons of olive oil over medium heat. Once hot, add the chopped fennel bulb and diced yellow onion to the pot, stirring frequently. Sauté for about 10 minutes.

Stir in the minced garlic, fennel seeds, and red pepper flakes. Cook for an additional 2 minutes, stirring often until the garlic is fragrant.

Pour in crushed tomatoes, seafood stock, and dry white wine. Season with kosher salt and black pepper. Bring to a boil, then reduce to low and simmer uncovered for 30 minutes.

Layer in the cod first, followed by shrimp, scallops, and mussels. Cover and cook for 10 minutes until the seafood is cooked.

Gently stir in anise-flavored liqueur, cover, and let sit for 3 minutes off the heat.

Ladle into bowls, garnish with parsley, and serve hot with crusty sourdough bread.