To prepare the stock, heat the olive oil in a small stock pot. Add the garlic, fennel, onion, celery, thyme and lemon. Sauté for about 3 - 5 minutes.
Add the fish bones, white wine and enough cold water to cover the ingredients. Bring the stock to a boil, reduce heat and simmer for 30 minutes.
Strain the stock and allow it to cool slightly before making the soup.
To prepare the rouille, combine all rouille ingredients except the olive oil (including the water from the saffron) in the bowl of a food processor fitted with a steel blade.
Pulse the mixture until the ingredients are well combined and finely chopped. With the processor running, gradually pour in the olive oil. Continue processing to form a thick paste. Remove the rouille from the processor and place in a bowl until ready to use.
To prepare the soup, preheat a 3.5- or 4-qt. sauce pan over medium heat until the rim of the pan is hot to the touch. Add the olive oil and heat an additional minute.
Add the leeks, garlic and shallots. Sauté for 5 minutes. Add the tomatoes, Pernod absinthe and 3 c. fish stock to the pan. Bring the mixture to a boil over medium heat and reduce to a low heat.
Add the sea bass and snapper to the pan. Allow the fish to poach for 5 minutes. Season the stock with salt and pepper to taste.
Add the mussels and clams to the soup and cover the pan. Steam the mussels and clams for 3 minutes, until they are open. Discard any mussels or clams that do not open.
Whisk together the remaining fish stock and one half of the rouille. Pour the mixture into the soup and stir to combine. Season again with salt and pepper to taste.
Ladle the bouillabaisse into individual serving bowls. Top each bowl with a slice of baguette. Spoon some of the remaining rouille over each slice of baguette and serve.