In a large stock pot over medium heat, add oil and saute onions, fennel, pepper and garlic until lightly browned. Add tomato paste and continue to cook until it browns. Add wine, tomato sauce, clam and lemon juices, water, bay leaves, red chili flakes, oregano, basil, salt, pepper and liqueur to the sauteed vegetables and simmer for 1 hour. Add crab to the sauce and let simmer for 20 to 30 minutes. Add clams and let simmer for 5 minutes, then add in cod and cook 4 to 5 minutes. DO NOT STIR. To finish add, shrimp.
Let cook 3 to 4 minutes until shrimp turn pink. Stir in parsley and serve immediately with fresh bread.