- Make the stew: In a heavy pot, heat oil and sauté onion, garlic, leeks, and fennel until slightly softened, about 8 to 10 minutes. Add tomatoes, tomato paste, potatoes, wine, fish stock, thyme, oregano, and bay leaf. Bring to a boil, then reduce heat and simmer for 30 minutes. Allow to cool slightly. Using a blender or food processor, carefully puree mixture. Pour through a fine mesh sieve and return to pot. Add orange zest, saffron, salt, and pepper. Cook over medium-low heat, stirring frequently, until somewhat reduced, about 20 to 30 minutes.
- Meanwhile, preheat the oven to 375 degrees. Brush baguette slices with melted butter and top with garlic. Toast in the oven until browned.
- Add rockfish to the sauce and cook until fish is almost done, about 8 to 10 minutes. Add shrimp and crabmeat and simmer until shrimp is pink, about 3 to 5 minutes longer. Reserve 1 cup of liquid for rouille.
- Make the rouille: Quarter potato and cook in reserved cooking liquid until tender. Drain, reserving the liquid. In a blender or food processor, finely chop garlic and chiles. Add potato, Tabasco, and oil. Process until mixture forms a paste. Slowly add reserved liquid until the mixture is the consistency of mayonnaise. Season with salt.
- To assemble: Place a piece of garlic bread into each bowl. Next, spoon in fish and add broth. Arrange shrimp and crabmeat on top and garnish with parsley. Serve rouille on the side.