Cheesy Lobster Casserole with Shell Pasta

A casserole of lobster and macaroni and cheese.

This cheesy lobster casserole borders on a seafood mac and cheese, but with more lobster-y flavor. In other words, it’s not mac and cheese with lobster, because you’d be starting with a cheese sauce. Instead, this is a lobster sauce with cheese. It starts with a creamy béchamel infused with real lobster stock, plenty of cooked lobster meat and a hefty dose of gruyere cheese not to mention al dente shell pasta. So, I guess you could think of it as a lobster mac n cheese — with a little more polish.

live lobster on a cutting board.

I’ve been on a bit of a lobster kick lately. We made those incredible sriracha lobster rolls, then a warm Connecticut lobster roll, then lobster ravioli sauce — and because I don’t waste anything — we turned the shells into an incredible homemade lobster stock.

This recipe was requested by my daughter, who’s been very enthusiastic about my recent focus on this luxe crustacean. Her words… “You need a lobster mac n cheese. Don’t worry, I’ll help!” Isn’t she selfless?

 Start with the creamy lobster sauce.

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  • Butter – for the bechamel sauce.
  • Dry Mustard – adds a bit more cheesy flavor to the cheese sauce.
  • Cayenne Pepper – for a hint of heat.
  • Flour – to thicken the bechamel.
  • Onion – when sauteed, it adds another layer of flavor and depth to the lobster casserole.
  • Lobster Stock – you can use my homemade stock or store-bought.
  • Milk – for the bechamel (white) sauce.
  • Cream adds more luxurious creaminess.
  • Salt and Pepper for seasoning (to taste).
  • Gruyere Cheese – one of the best for melting.
  • Lobster Meat – you can cook the lobster yourself and make the stock or buy a package of cooked lobster chunks.
cooked lobster meat from a steamed lobster. Use the shells for homemade seafood stock for the lobster béchamel.

How to deal with a live lobster

You can’t have lobster casserole without lobster, right? I used a 1 ½ pounder for this recipe.

If you’re squeamish about dispatching the crustacean, you can have the fishmonger (or grocer) steam it for you, however, if you’ve got a live lobster, follow these simple instructions for cooking it.

Note: Live lobsters usually come with rubber bands over their claws — so they can’t nip at you. Don’t take those bands off until it’s dead. 

Now onto the unpleasant business at hand… Julia Child says “a serious cook really must face up to the task personally.”

I agree. Having grown up in Virginia’s Chesapeake Bay region, I’ve steamed bushels of lively blue crabs and slurped more than my share of oysters on the half-shell (yes, they’re alive when you eat them – don’t judge).

How to humanely kill a lobster

  • Use a pot large enough to comfortably handle the lobster. Fill it with about 2 inches of water and add a tablespoon of salt.
  • Set a steaming rack inside the pot and bring the water to a full boil with the lid on. 
  • If you want to put it quickly out of its misery before steaming it, set the lobster on a cutting board, and hold it firmly in place just behind the shoulders.
  • Take a large chef’s knife and put the point behind the lobsters eyes. 
  • Quickly plunge the knife down through the carapace. The legs may still move, but the lobster will be dead. Offer a silent prayer for his sacrifice and put him in the pot.
  • Cook the crustacean according to this chart, depending on how big it is.

Lobster cooking times (steaming)

Lobster Cooking Times Chart

Cooked lobster meat will turn from translucent to white.

Let the lobster cool until it’s easy enough to handle without burning yourself and use a pair of kitchen sheers, lobster crackers  and seafood picks to remove the cooked meat from the tail, claws and legs and set aside. If you don’t already have lobster stock made up (or purchased) you can use the leftover shells to make a stock. This easy homemade lobster stock recipe is my favorite.

making lobster stock for the seafood mac and cheese

The sauce for our lobster mac n cheese starts with a simple roux, but rather than a traditional white sauce (béchamel) we add the lobster stock to give it more of a Newberg flair. This gives our lobster casserole a seafood infusion beyond just chunks of lobster meat.

Making béchamel for the seafood mac and cheese

  1. Melt the butter in a medium saucepan over medium high heat and whisk in the dry mustard, cayenne pepper and flour, cooking and stirring constantly until there are no dry bits left and the mixture is like a paste. (This is called a roux — pronounced “roo”).
  2. Add the onions and sauce in the butter mixture until they’re slightly softened and translucent.
  3. Slowly add warm lobster stock, stirring constantly.
  4. Stir in the milk and cream and bring the mixture just to the boiling point, whisking constantly. Cook for a minute until the sauce thickens and is velvety.
Making the roux and sautéing onions for cheesy lobster casserole.

Adding al dente pasta to the seafood casserole

The lobster stock gives the seafood sauce a slightly rosy pink color, echoing the hue of crustacean itself. When the creamy lobster béchamel is ready, stir in the cooked pasta shells and toss well so that every nook and cranny is coated and filled with the rich seafood sauce. The lobster mac n cheese is starting to come together now.

Stirring the seafood béchamel and adding shell pasta for the mac and cheese casserole.

Assembling the casserole

  1. Add the cooked lobster and 1 1/2 cups of the shredded gruyere cheese to the seafood pasta mixture and toss well to combine.
  2. Transfer the seafood mac and cheese to a prepared baking dish and cover with fresh breadcrumbs and remaining cheese.
  3. Bake until the casserole is bubbly and crust has browned slightly.
adding gruyere cheese and lobster to the pasta and adding to a casserole dish for the ultimate lobster mac n cheese.

Baking lobster mac n cheese

It doesn’t take long to warm this lobster casserole through. In a mere fifteen to twenty minutes your seafood mac and cheese  will be golden, oozy (technical cooking term) and ready to eat. Emily and Scott, not wanting to miss out on the final countdown, stayed in the kitchen while the casserole was baking. Holding vigil by the oven and grinning like they’d gotten away with something.

topping lobster casserole with fresh breadcrumbs to bake.

This lobster casserole tastes like lobster

This luscious lobster mac and cheese is rich, without being overly so. The briny seafood aroma is prevalant and although there is 2 cups of gruyere cheese in the dish, the predominant flavor is of the shellfish thanks to the creamy seafood béchamel, not to mention the chunks of lobster meat. This recipe serves 4-6 people depending on appetite and what you’re serving with it and can be the main course or a decadent side dish to a good steak or veal chop. We like it with a fresh green salad and chilled Chardonnay or Sauvignon Blanc for the ultimate comfort food.

Baked Lobster Casserole hot from the oven.

More macaroni and cheese recipes you might like:

A spoonful of seafood mac and a cheese.

More seafood dishes you might like: 

Print Pin
5 from 5 votes

Lobster Shells and Cheese

Completely decadent and worth every bit of it!
Author: Lisa Lotts
Course Main Course
Cuisine American
Keyword lobster, pasta
Dietary Restrictions Pescatarian
Prep Time 20 minutes
Cook Time 40 minutes
Total Time 1 hour
Servings 6



  • 1 slice bread
  • 1 teaspoon butter
  • 1 tablespoon parsley


  • 3 tablespoons unsalted butter
  • ½ teaspoon dry mustard
  • pinch cayenne pepper
  • 3 tablespoons all purpose flour
  • 1 small onion or large shallot chopped
  • 1 ½ cups lobster stock recipe on this site or use good quality store bought.
  • 1 cup milk
  • ½ cup cream
  • 1 teaspoon kosher salt
  • ¼ teaspoon black pepper freshly ground
  • 2 cups gruyere cheese shredded , divided


  • ¾ pound shell pasta
  • 2 cups cooked lobster chunks from about 2 pounds of lobster
  • 2 tablespoons parsley chopped fresh



  • Cook the pasta 2 minutes short of al dente according to package directions — so if “al dente” is 10 minutes, cook for 8. Pour pasta into a colander and rinse with cold water to stop the cooking. Spread the pasta on a rimmed sheet pan and drizzle with a little olive oil. Toss to coat and set aside.


  • In a mini-prep food processor add the bread, butter and parsley and pulse until crumbs form. Set aside.


  • Spray an 8″ casserole dish with vegetable spray and set aside. Preheat the oven to 350°.
  • In a large saucepan, melt the 3 tablespoons of butter over medium to medium high heat and whisk in the mustard, cayenne pepper and flour. Stir for one minute over the heat then add the lobster stock and continue whisking — mixture will absorb and thicken quickly.
  • Stir in the onion and cook until slightly softened and translucent.
  • Add the milk and cream and continue to whisk. Heat the mixture just to the boiling point, whisking the whole time until it thickens — and being careful to scrape the bottom and sides of the pan so that the flour mixture doesn’t settle onto the bottom.
  • Remove the sauce from heat and stir in the cooked pasta. Add the lobster and 1 3/4 cups gruyere cheese and parsley. Stir to combine. Pour the pasta mixture into the prepared dish. Sprinkle with breadcrumbs and remaining gruyere cheese.
  • Bake for 15 minutes or until breadcrumbs are lightly browned and casserole is bubbly. Jump up and down because it’s ready and your about to be a very happy camper!


To reheat, microwave for 30 seconds to 1 minute or heat in a low 300° oven for 10-15 minutes.


Calories: 599kcal | Carbohydrates: 52g | Protein: 28g | Fat: 31g | Saturated Fat: 18g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 8g | Trans Fat: 0.3g | Cholesterol: 119mg | Sodium: 1039mg | Potassium: 380mg | Fiber: 2g | Sugar: 5g | Vitamin A: 1143IU | Vitamin C: 4mg | Calcium: 570mg | Iron: 2mg

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  1. 5 stars
    Just made this for dinner. Very good, and good lobster flavor. It’s a lot of work. Like, A LOT. Was in the kitchen for hours prepping the 2 lobsters, making the broth, making the casserole. I used the broth recipe recommended and the shallots over onions. We can’t buy lobster broth here so making the broth was necessary.

    Next time I would put a bit more breadcrumbs to make a crustier top. Maybe reduce the sauce more or make it slightly saltier. Spouse recommended we add scallops to it next time.

    But I’m happy with it and it was enjoyed by all.

  2. Jackie Cooper says:

    Hi Lisa

    I can’t find the link to the lobster stock?

    1. Hi Jackie! – the recipe plugin that I use doesn’t let me embed links, so I included the link within the body copy of my post. But here is the url. Also, there is a search function on the right hand rail. It can be a little buggy, but if you type lobster stock, it should go to the recipe.

    1. I know, it’s a bit hedonistic, isn’t it?

  3. This dish sounds so amazing! Love mac n cheese anything. Gruyere and lobster, yummy!

    1. Thank you, Amber – I’m glad you like it!

  4. Oh my heck that looks absolutely to die for. I’ve never bought a lobster to cook at home but I’m so stoked to try it. Everything is just perfect in that dish.

    1. Cooking lobster is easy to do — after you get past that whole “cooked alive” thing.

  5. Wow!! This mac and cheese with lobster looks amazing!! Perfect with a glass of Pinot!! Yummy!

  6. The lobster shell cheese bake look so gorgeous and delicious. Such a comforting bowl for a weekend nosh 🙂

    1. Glad you like it Molly! It’s total comfort food – with a fancy twist!

  7. Holy smokes, this looks delicious. Must try this recipe!

  8. recipesfromapantry says:

    My OH has been drooling over my shoulder at your recipe and has asked my quite indignantly why I don’t make food like this. LOL.

    1. I know – it’s like comfort food at it’s most decadent!

  9. 5 stars
    Wow, thank you. What a decadent dinner! Love the lobster stock in the sauce!!

    1. It’s actually a b?chamel made with homemade lobster stock and it doesn’t suck!

    1. I don’t know many people who wouldn’t be happy with this one! People with shellfish allergies?

  10. You had me at briny windswept summer afternoon on the Maine coast…I used to live on the Maine coast and I think this is pretty much the ultimate luxurious meal on the planet, bravo!

    1. I’ve never even visited Maine – but I’ve told my husband I definitely want to go! When is the best time of year? I’m thinking August, but I don’t know.