1. Build the Flavor Base

• In a large Dutch oven or heavy pot, heat olive oil over medium heat.
• Add onion, fennel (if using), and bell pepper; sauté until softened (about 5 minutes).
• Add garlic and red pepper flakes; cook for 1 minute more.
• Stir in tomato paste and cook for 2–3 minutes to deepen the flavor.

2. Simmer the Broth

• Add crushed tomatoes, white wine, seafood stock, bay leaf, oregano, salt, and pepper.
• Bring to a boil, then reduce heat and simmer uncovered for 20 minutes to develop flavor.

3. Add the Seafood

• Add clams and mussels first, cover and cook 5 minutes.
• Add shrimp, scallops, and fish. Simmer gently for 5–7 minutes, or until all shellfish open and seafood is just cooked through.
• Discard any unopened clams or mussels.

4. Finish and Serve

• Stir in fresh parsley.
• Taste and adjust seasoning if needed.
• Serve hot in bowls with lemon wedges and lots of crusty bread for dipping.