Seafood Thermidor

Light and easy seafood dishes make tasty weeknight meals, but special occasions call for decadence. Seafood thermidor is one of those vintage recipes that deserves a comeback. Chock-full of shrimp and flaky white fish, this seafood thermidor recipe tastes like you’ve splurged and spent hours in the kitchen. Instead, you created an affordable restaurant-quality masterpiece in no time at all.

This seafood thermidor is similar to lobster thermidor but is much easier to make and less expensive. The basic process is the same for both: Heat the seafood in a light cream sauce, add the cheese, top with the bread crumbs, and broil until golden brown and bubbly. The main difference between seafood and lobster thermidors is the latter is often broiled and presented in the lobster shell. Our take may lack the stunning presentation of the halved lobster shells, but it’s delicious enough that you won’t miss the flash.

What is thermidor sauce?

Thermidor sauce originated in France and was most likely named after a month on the now-abandoned French Revolution calendar. Some stories say that Napoleon first ate the dish during that month, although others claim a Parisian chef created the meal to attract theatergoers after the controversial play Thermidor opened in the city.

An authentic lobster thermidor sauce generally contains eggs, Cognac or white wine, heavy cream, shallots and a dash of mustard. Our shrimp thermidor sauce is similar, with a few tablespoons of powdered soup mix for flavor. Our recipe even reduces the calories in the creamy sauce by using lower-fat milk and cheese.

Lobster thermidor is often confused with another creamy seafood dish: lobster Newburg. Instead of the flour-thickened thermidor sauce, Newburg sauce is made with cream, egg yolks, sherry and sometimes a bit of cayenne.

Seafood Thermidor Ingredients

• Butter: All great sauces begin with butter. Use salted or unsalted, but if using salted, you may need to adjust the seasoning later.
• Onion: A small amount of chopped onion significantly impacts this sauce. The goal is to make the chopped pieces soft, not take them all the way to caramelized onions.
• Powdered soup mix: Homemade cream-style soup mix has an array of flavors often found in a store-bought can of condensed soup. For an easy substitute, grab a packet of onion soup and dip mix.
• Flour: Stirring flour into melted butter is how you make roux, a reliable sauce thickener. Adding the onion and the soup mix early in the seafood thermidor recipe doesn’t affect the paste’s thickening power.
• Liquids: Milk, white wine or chicken broth, and lemon juice add layers of flavor that you wouldn’t achieve by using just one of these liquids. For a pescatarian-friendly dish, be sure to use the wine instead of the chicken broth.
• Fish: Firm white fish, such as cod or haddock, flakes apart in this dish to resemble the texture of lobster knuckle and claw meat. Cook the cubes briefly on the stovetop so that they stay tender after broiling.
• Shrimp: Raw shrimp have a tenderer texture, closer to that of lobster tail meat, than frozen precooked shrimp would in this recipe. Once they turn pink, pull the shrimp from the stove; they’ll continue to cook as the sauce bubbles in the oven. You can use fresh or frozen uncooked shrimp; don’t use anything already cooked.
• Mozzarella cheese: Part-skim mozzarella along with 2% milk lower the calories in this typically rich sauce. It takes only a couple of tablespoons of mozzarella to make shrimp thermidor sauce thick and slightly gooey.
• Parsley: Mince just the parsley leaves; the stems tend to be bitter—and tougher farther from the leaf. There are plenty of ways to use up parsley if you have too much left over.
• Topping: Melted butter, bread crumbs and grated Parmesan cheese make a crunchy topping that turns golden under a broiler’s heat. Keep a close watch while the seafood thermidor recipe is in the oven so that the surface doesn’t burn.

Directions

Step 1: Make the roux

In a large saucepan, saute the onion in 1 tablespoon butter until tender. Combine the soup mix and flour, and then stir the dry ingredients into the onion until blended.

Step 2: Make the sauce

Gradually whisk in the milk. Stir in the wine or broth and lemon juice. Bring the liquids to a boil, and then cook and stir for one to two minutes or until thickened.

Editor’s Tip: You may want to switch from a whisk to a rubber spatula to get any residual flour paste out of the corners of the saucepan.

Step 3: Add the seafood

Add the cod and cook for 90 seconds. Stir in the shrimp and cook for one minute longer or until the fish flakes easily with a fork and the shrimp turn pink.

Editor’s Tip: To perfectly cook (and not overcook) shrimp, cook them until they curl into a nice C shape. When overcooked, shrimp turn matte white or gray and curl tightly into an O shape. It’s easy to remember: C = cooked and O = overcooked.

Step 4: Mix in the cheese

Remove the pan from the heat. Stir in the mozzarella cheese and parsley until the cheese is melted.

Step 5: Prepare to bake

Transfer the seafood thermidor to a 3-cup baking dish coated with cooking spray. Melt the remaining 1 tablespoon butter, and toss it with the bread crumbs and Parmesan cheese.

Step 6: Add the topping and bake

Sprinkle the topping over the seafood mixture. Broil the dish 4 to 6 inches from the heat for three minutes or until the topping is golden.

JOSH RINK FOR TASTE OF HOME

Recipe Variations

• Choose sustainable options: Orange roughy has been noted on seafood watch lists as a fish to avoid because of concerns about overfishing and the effects of trawling in deep-sea coral and sponge habitat. Pacific cod caught in North American waters and haddock are environmentally smarter choices for this dish. Whiteleg shrimp, either farmed using safe practices or sustainably caught in U.S. waters, are among the types of shrimp recommended by organizations that promote sustainable fishing practices.
• Use other seafood: Instead of mixing fish and shrimp, make shrimp thermidor with just the shellfish. Crabmeat could be substituted for the finfish, as could monkfish, also known as poor man’s lobster because its flesh resembles lobster meat at a fraction of the price.
• Substitute condensed soup: Replace the homemade soup mix and milk with half a can of condensed cream of chicken soup. For a flavor variation or pescatarian dish, use condensed cream of mushroom or celery soup instead and white wine or vegetable stock rather than chicken broth.
• Add more flavor: Lobster thermidor often includes a little dry or prepared mustard for extra flavor. Add a pinch of cayenne if you like a little heat. Make this seafood thermidor recipe richer by substituting heavy cream for the 2% milk, brandy for the white wine and Gruyere for the mozzarella cheese.

How to Store Seafood Thermidor

Seafood thermidor tastes best when you eat it straight away, but leftovers can be refrigerated for a later meal. Let the dish cool completely at room temperature, but be sure to pack it away within two hours for safety. Transfer the seafood in its creamy sauce to an airtight container before placing it in the refrigerator. This recipe doesn’t freeze well because the cream sauce usually separates when defrosted, becoming watery and thin.

How long does seafood thermidor last?

Seafood thermidor keeps for up to four days in an airtight container in the refrigerator, but expect the quality to deteriorate the longer you hold on to the leftovers. Rather than trying to make it last, prepare this dish just before you plan to serve it. If you do expect to store leftovers, pack up the sauce without the topping so that it doesn’t become soggy when you reheat the dish.

How do you reheat seafood thermidor?

A conventional or toaster oven works best when reheating this seafood thermidor recipe. In the microwave, it’s easy to overheat the edges of the sauce and turn the fish and shrimp tough and rubbery. Transfer the creamy seafood to a baking dish and warm it in a 350°F oven for 10 to 15 minutes or until an instant-read thermometer inserted in the center reads 165°. Sprinkle on the topping, if desired, and broil until it turns golden.

Seafood Thermidor Tips

JOSH RINK FOR TASTE OF HOME

What’s the best way to clean and devein shrimp?

Learning how to clean shrimp ensures the best quality product. Choose uncooked frozen shrimp with the head removed so that you need to only peel off the body and tail shell. Once defrosted, pinch the flesh in one hand and pull back the shell with the other. If you want to remove the vein, tease it out with a paring knife after you remove the shell.

If a shrimp tears and leaves a little flesh toward the tail, you can still use it in shrimp thermidor. Just squeeze and wiggle the flesh loose and add it to your pile of chopped shrimp. You can do the same with many other juicy shrimp recipes.

Are there other ways to use thermidor sauce?

If seafood isn’t your thing, use precooked chicken with the thermidor sauce instead. Cut it into cubes as you would the fish. Vegetarians often substitute hearts of palm for lobster and white fish because they have a similar flaky texture and mild flavor. For a more intensely flavored vegetarian dish, use this sauce with hearty mushrooms or cubes of eggplant, sticking with white wine or choosing vegetable stock for the secondary liquid. Make sure that the soup mix you use is vegetarian too.

What can you serve with seafood thermidor?

Light sides work well with this creamy seafood dish. One of these simple side salad recipes lets the main course hog the spotlight. Serve shrimp thermidor with saffron-infused rice or a light and easy pesto pasta that can be loaded onto a fork with a little of the shrimp and sauce. Roasted vegetables, like this rosemary roasted potatoes and asparagus recipe, also pair well with the cream sauce. If you choose to cook just a green vegetable, like stir-fried zucchini, serve hunks of crusty bread on the side to soak up the last of the rich seafood sauce.