Lobster/crayfish Mornay

It's pretty hard to beat the comforting taste and texture of a mornay sauce with the luxury of a crayfish or lobster. It's one of the classic ways to enjoy crayfish and lobster, along with Lobster Thermidor and a simple Lobster/Crayfish with Garlic Butter.

It's easy to make too, taking only around 15 minutes to make the mornay sauce and grill it to golden perfection.

This recipe is written using a cooked crayfish or lobster, as that's how they're most commonly sold. If you've caught one or purchased one that's uncooked, you can follow my post on how to cook crayfish/lobster which will walk you through humanely dispatching and cooking the lobster.

Lobster or crayfish mornay ingredients

Check out the recipe card further down the post for comprehensive ingredients and quantities.

• Crayfish or lobster - around 800g (1.75 lbs) will serve two people. I've made the assumption that you will buy a cooked crayfish/lobster, but if you have bought it raw or caught it, you can follow my post on how to cook crayfish and lobster
• Normal mornay ingredients - butter, plain flour and milk.
• Cheese is used in both the mornay sauce and as a topping when grilling the crayfish/lobster:
  • Gruyère or another nutty cheese such as cheddar, Emmental or Swiss.
  • Parmesan or pecorino.
• A little cream can be added for richness if you'd like.
• Dijon mustard.
• Spice from nutmeg, salt and white pepper.
• Optionally, you can top the mornay with breadcrumbs and parsley for a little crunch when grilling.

How to make Lobster or crayfish mornay

Check out the recipe card further down the post for comprehensive instructions.

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1. Make the roux by melting butter and combining with flour.
2. Make the bechamel by slowly whisking milk into the roux.
3. Halve the crayfish/lobster and remove the intestines and tail meat.
4. Slice the tail meat into bite sized pieces.
5. Make mornay by adding half the cheese, nutmeg and Dijon to the bechamel.
6. Add lobster or crayfish meat to mornay and warm it through.
7. Place the lobster meat and mornay sauce into the shell.
8. Top with the reserved cheese, and breadcrumbs and parsley if using.
9. Grill/broil the lobster or crayfish at a high temperature or until the cheese is golden brown and melted.

How to cut or halve a crayfish or lobster

It's easier and safer to halve a crayfish/lobster with the underside facing upwards. The shell is not as thick, which makes it easier to do.

Place the crayfish or lobster belly-side up on a chopping board. Insert the knife at the base of the head (1), and cut downward through the body and tail (2).

Split the crayfish or lobster in half (3) and then remove the intestines (the green "guts" or tomalley) and intestinal tract, which is the line you see through the tail (4).

Lobster (or Crayfish) Mornay

5 from 1 votes

Sam Knight

Lobster/Crayfish Christmas Easter Summer Australian cuisine

Prep	Cook	Total
5 mins	15 mins	20 mins

Serves 2

Lobster Mornay is a favourite baked seafood dish made with a creamy cheese sauce, perfect for showcasing fresh lobster or crayfish. This easy recipe takes just 15 minutes and delivers rich and golden cheesy perfection.

• 30g (2 tbsp) unsalted butter
• 2 tbsp plain flour
• 250ml (1 cup, 8 1/2 fl oz.) whole milk
• 60ml (1/4 cup, 4 tbsp) cream optional - adds richness
• 100g (3.5 oz.) grated Gruyère cheese, halved or use cheddar, Emmental or a Swiss cheese
• 50g (1.75 oz) grated Parmesan cheese, halved or use pecorino
• 1 tablespoon Dijon mustard
• Freshly grated nutmeg, to taste
• Salt and white pepper, to taste see note 1
• 800g (1.75 lbs) crayfish or lobster cooked, see note 1
• Breadcrumbs optional
• Finely sliced parsley optional

Steps

1. Make the roux – melt butter in a saucepan over medium heat. Stir in flour and cook, whisking occasionally, for about 30 seconds until bubbling.
2. Make bechamel - gradually whisk in the milk to form a smooth sauce, taking care to make sure the milk is incorporated and no lumps remain. Reduce heat to low. Stir every 30 seconds while prepping the crayfish or lobster.
3. Preheat your grill/broiler to its highest temperature. Remove any trays from your oven to avoid damaging them.
4. Halve the crayfish/lobster - place the crayfish or lobster belly-side up on a chopping board. Insert the knife at the base of the head, and cut downward through the body and tail.
5. Remove tail meat - remove the guts and intestines with a spoon and remove the intestinal tract from the tail. Finally, remove the tail meat by pulling it out in one piece.
6. Slice meat - slice the tail meat into bite sized pieces.
7. Make mornay - whisk cream into the béchamel (if using). Add half the Gruyère, half the Parmesan, mustard, nutmeg. Stir until smooth, and then season to taste with salt and white pepper.
8. Add meat to mornay - add the tail meat to the mornay sauce and stir gently to warm through.
9. Return meat to shell - use a spoon to return the meat to the shell, dividing evenly between both halves. Add any left over sauce to over the top if you'd like - If you’re not using all the sauce, make sure to remove all the meat from it before discarding the rest of the sauce.
10. Add extra cheese - add the remaining cheese evenly over both halves of the crayfish/lobster. If using the breadcrumbs and parsley, sprinkle both over the top of the cheese.
11. Grill/Broil - place the two halves of the crayfish/lobster on a tray suitable for high heat. Place under the grill/broiler and cook until golden brown and the cheese is melted.
12. Serve with crusty bread and simple garden salad.

Notes

1. Crayfish size - around 800g (1.75 lbs) will serve two people. If you're serving a number of sides, you might get away with a 600-700g (1.3 - 1.5 lbs) crayfish/lobster. Alternatively, if you're not serving any sides at all, you might want a 900g-1kg (2 - 2.2 lbs) cray/lobster. The mornay sauce makes enough for up to a 1kg cray.
2. Cooking crayfish - I have a post detailing how to cook and humanely dispatch your crayfish/lobster. If you purchase an uncooked fish or catch one, follow the instructions in that post to prepare it.
3. Warming the crayfish/lobster - the lobster is already cooked, so the aim of putting it in the mornay is to gently warm it through before serving. Do this at a low temperature to give you control - overcooking the meat can make it mushy or chewy.
4. Salt - cheese is salty - add a little salt at a time, stir well and taste as you go.
5. Pepper - if you choose to add pepper, use white pepper and add it gradually. White pepper is preferable because it won't show up as black specks in the mornay.
6. Mornay - if your mornay is too gloopy, add a splash of milk and whisk it through until you have a looser consistency.
7. Grilling/broiling warning - the tray you cook it on will be hit with a lot of heat. Make sure that it's safe for use at a high temperature (i.e. not a non-stick tray) and be careful when you remove it. The cheese will go from being golden brown to burnt very quickly so keep a check it regularly.