In a saucepan, cook the sliced carrot and the sliced leek white for 10 minutes with a drizzle of olive oil and the bay leaf. Stir occasionally.
Cut the fish into large pieces and lightly flour it on all sides, as well as the scallops and langoustines.
In another pan, brown the chopped shallot with olive oil. Add the fish and seafood and gently but quickly brown all sides.
Divide the fish and vegetables into the casserole dishes, sprinkle with white wine, add a few drops of lemon juice. Add salt and pepper.
Add 2 spoons of fresh cream to each of the cassolettes, sprinkle with breadcrumbs and grated parmesan. I also like to sometimes add a few buckwheat seeds on top, it adds a little crunch.
Bake for about 15 minutes, until the top of the casserole is golden brown. You can go under the grill for 1 or 2 minutes. Be careful not to overcook.
Serve with white rice or mashed potatoes for example.