Crush garlic with sea salt into a paste.
Whisk garlic, mustard, and egg yolks in a bowl.
Slowly whisk in vegetable and olive oils to form an emulsion.
Add lemon juice and salt, then chill for one hour.
Finely chop shallots and garlic, and roughly chop tomatoes.
Sweat shallots and garlic in olive oil for five minutes.
Stir in thyme, tomatoes, saffron, and Pastis; cook for two minutes.
Add white wine and simmer gently for several minutes.
Cut fish into chunks and clean shellfish.
Add fish, langoustines, prawns, and squid rings to the pan.
Add enough water to just cover the fish.
Cover and simmer the mixture gently for eight minutes.
Add mussels and clams, cooking until shells open.
Discard unopened shellfish and season with salt, pepper, and herbs.
Spread aioli on grilled bread and serve with the broth and seafood.