Julia Child's Lobster Thermidor Recipe with Mushrooms and Cognac (2024)

Learn to make Julia Child's Lobster Thermidor recipe. A creamy and decadent lobster dish with white wine, mushrooms and splash of cognac.

If you love hearty seafood recipes full of fresh seafood such as this rustic bouillabaisse recipe, add this next cooking project to the list!

I really don't know how to introduce this dish, the title explains it all. Julia Child's lobster thermidor! Joe asked for this for his birthday and it has been bookmarked in my Julia Child book for months.

I have to be completely honest, I was skeptical to post this just because of the photos! When you're a "food blogger" food photography is everything and we eat with our eyes. Because I took these photos at night they weren't at the quality as my other photos. But I couldn't keep this dish away from you! I am first a cook before photographer and that's what counts. plus, this classic lobster thermidor recipe is freakin' amazing and shouldn't be hidden.

Lobster Thermidor Sauce is decadent and worth the effort

Thick creamy sauce with lobster stock and sweet lobster meat all through out. It is amazing, decadent and so rich. It takes time but is so worth it! I read through the recipe and gasped at the ingredients! Cream...yolks...more cream...butter...and if that wasn't enough, a little cheese to top it off with. But alas, this is what Joe requested. When I asked him "What would you like for your birthday dinner?" thinking, oh great, we can go out and enjoy a nice meal that someone else prepares. But no, my...husband said "Lobster Thermidor" and of course not just any lobster, but Julia Child's lobster thermidor recipe.

I've done a few Julia Child dishes and I have learned that it is most helpful to read the entire recipe before getting into it especially since this one has a few steps and takes time. Also, I don't know why I didn't photograph each step like I usually do! I hope all the steps are explained clearly. Don't hesitate to email me asking for help! 🙂

How to make the traditional lobster thermidor recipe

Steaming the lobsters

1) In a large pot (that will fit 2 large lobsters), simmer wine, water, vegetables, herbs, and seasonings for 15 minutes. Then bring to a rolling boil and add the live lobsters. Cover and boil for about 20 minutes or until the lobsters are done and turn bright red.

2) While the lobsters are steaming, stew the mushrooms slowly in a pan with 1Tb butter, lemon juice, and salt for about 10 minutes until then begin to soften. Set aside.

The sauce

3) When the lobsters are done, remove them from the pot and put over ice. We filled our sink with ice and put the lobsters right in to cool down.

4) Save the mushroom cooking liquid and add that to the lobster stock. Bring to a boil until it has reduced to about 2 cups. (This is amazing lobster stock). Strain the stock through a sieve and discard vegetables and herbs and allow stock to stay at a simmer.

5) In another pot, cook 5 Tb butter and 6Tb flour slowly for 2 minutes without browning.Take off heat and whisk in the lobster stock. Bring to a boil while whisking for 1 minute until it gets thick. Take off heat and whisk in 1 Tb heavy cream. Set aside.

6) In another bowl, whisk together the egg yolks, dry mustard, ½ c heavy cream and pinch of cayenne. Add the reserved cream mixture (that is sitting on the stove) to the egg mixture. Add it slowly while whisking and then return sauce to the pan. Stir the sauce every so often with a wooden spoon. Bring sauce to a boil for 2 minutes and then simmer. You want the sauce thick enough to coat the back of the wooden spoon. Taste for seasoning.

Sauteing the lobster meat:

7) Split the lobsters in half lengthwise, keeping the shell halves intact and remove the meat from the lobster tails and claws, and cut it into ½ inch pieces. Clean the lobster shells well and dry them. Reserve shells.

8) In another pan, saute lobster meat with 4Tb butter for about 5 minutes until the lobster meat turns a dark rosy color. Pour in cognac carefully and bring to a boil to cook off alcohol while shaking the pan. The liquid should reduce.

Final assembly:

9) Preheat oven to 425 degrees. In a large pan or bowl, mix together the mushrooms, lobster sauce and lobster meat.

10) On a baking sheet, place the 4 lobster shell halves down and wrap the bottom part of the shell with tin foil. This will help them the shelves stay in place.

11) Use the wooden spoon to scoop the lobster mixture into the shells. Don't over fill. Sprinkle with grated Parmesan cheese on top and place in upper ⅓ of oven. Allow to cook for 10-15 minutes until the top begins to brown.

More shellfish inspiration

And if you are looking for more Julia Child recipes to try, I'd love to suggest Julia Child's cheese souffle or something a bit more manageable, Julia Child's Mussels Mariniere.