Cook the fish:
Poach the cod in a pot of simmering salted water for 5 to 7 minutes. Drain carefully and coarsely crumble.
Make the béchamel sauce:
Melt the butter in a saucepan, add the flour, and stir to form a roux.
Gradually add the milk and whisk until thickened.
Add the crème fraîche, salt, pepper, a pinch of nutmeg, and the chopped shallot. Simmer for 2 to 3 minutes.
Assembly:
In a large bowl, combine the fish, shrimp, mussels, half the cheese, and the béchamel sauce.
Add a squeeze of lemon juice to enhance the flavors, if desired.
Gratin:
Transfer everything to a buttered baking dish. Sprinkle with the remaining cheese.
Bake at 200°C (390°F) for 20 to 25 minutes, or until golden brown.
Serve hot, sprinkled with fresh parsley, accompanied by rice, steamed potatoes or a nice green salad.
Bon appetit!
ADVERTISEMENT
