Seafood Thermidor

Thermidor is the French preparation that originated in the late 19th century at a Parisian restaurant celebrating a play of the same name. The technique gives any seafood the regal treatment: poach it gently, fold it into a rich bechamel-style sauce with mustard and wine, top with breadcrumbs and cheese, and broil until the surface bubbles golden. This version goes the seafood medley route with a mix of fish fillets, crab, shrimp, scallops, or clams, which is more affordable than the classic lobster thermidor while still delivering the same indulgent flavor. Poaching the seafood briefly in lemon-onion water before saucing it is the move that prevents overcooking. The seafood firms up just enough to hold its shape in the casserole but stays tender when it bakes a final time under the broiler. The cream of shrimp soup and a splash of white wine build a sauce that’s silky and concentrated, while Dijon mustard cuts through the richness with that sharp tang that defines a true thermidor. Serve over rice or in puff pastry shells for a dinner party showpiece.

Pro Tips

• Don’t oversimmer the seafood. Four minutes is plenty, and the residual heat continues cooking it even after draining.
• Drain the seafood thoroughly before folding into the sauce. Excess water dilutes the cream sauce and ruins the texture.
• Whisk the soup-flour mixture before adding milk to prevent lumps. Constant stirring is key to a smooth sauce.
• Watch the broiler closely. Surface goes from golden to burnt in under a minute.
• Let it rest 5 minutes before serving so the sauce thickens and stops bubbling.

Variations

• Use cream of mushroom or cream of celery soup instead of cream of shrimp.
• Add a splash of cognac or sherry along with the wine for the classic French touch.
• Top with Gruyere instead of mozzarella for a more authentic French flavor profile.