Lobster Thermidor
Lobster thermidor is a French restaurant classic that is easier at home than it looks, as long as you start with cooked lobsters. The meat is warmed in a mustard, white wine and cream sauce, spooned back into the shells, scattered with cheese and grilled until bubbling. It makes a showpiece dinner for two, with most of the work done before the grill goes on.
- Total
- 37 min
- Prep
- 20 min
- Cook
- 17 min
- Serves
- 2
- Per serving
- 650kcal
Buying and preparing lobster for lobster thermidor
Use cooked lobsters, which most fishmongers and larger supermarkets sell whole, usually chilled and with a use-by date. A 500g lobster gives about 130g of meat, enough for one generous portion. If you buy live lobsters, they need to be killed humanely and boiled first, as in boiled lobster.
The shells are your serving dishes, so split them carefully and keep them intact. Splitting is easier with a very sharp, heavy knife, and a damp tea towel under the board stops it slipping.
Cooking lobster thermidor
Tap a time to start a timer.
- Split the lobsters Lay a lobster on a board and hold it firmly. Push the tip of a large heavy knife into the middle of the head and cut down through it, then turn the lobster round and cut through the tail to split it in half lengthways. Remove the stomach sac from the head and the dark vein along the tail, and discard them.
- Remove the meat Lift the meat out of the tail and body. Crack the claws with the lobster crackers and take out the meat. Wipe the four shell halves clean with kitchen paper, then cut the meat into chunks about 2cm across.
- Start the sauce Heat the grill to high. Melt the butter in a small saucepan over a medium heat and cook the shallot for until soft. Add the wine and boil for until it has reduced by half.
- Finish the sauce Stir in the mustard and cream and simmer gently for , until the sauce is thick enough to coat the back of a spoon. Add the lobster and parsley and warm through for . Season with pepper and taste before adding salt.
- Fill and grill Sit the shells on a baking tray, steadied with scrunched foil if they tip. Spoon in the lobster mixture and scatter over the cheese. Grill about 15cm from the heat for until bubbling and golden. Serve at once with lemon wedges.
What to serve with lobster thermidor
The sauce is rich, so serve it with something simple: a green salad with a sharp dressing, steamed green beans or asparagus, and crusty bread or buttered new potatoes to mop up the sauce in the shell. Dry white wine, such as a Chablis, is the classic pairing.
For a simpler way to cook lobster, pan-fried lobster tail needs far less preparation.
Common problems and fixes for Lobster Thermidor
- The sauce is runny.
- Simmer it for another minute or two before the lobster goes in. Do not reduce it after adding the lobster, as that toughens the meat.
- The sauce looks greasy or has split.
- It has boiled too hard. Keep it at a gentle simmer, and if it splits, whisk in a spoonful of cold cream off the heat.
- The lobster is chewy.
- Cooked lobster only needs to be warmed in the sauce for a minute and under the grill for a few minutes. Longer than that and it turns rubbery.
Frequently asked questions about Lobster Thermidor
How do you know when lobster thermidor is ready?
The topping is golden and bubbling and the filling is steaming hot. The lobster is already cooked, so about 5 minutes under a hot grill is enough to heat it through.
Can you use frozen lobster?
Yes, but defrost it fully in the fridge overnight and pat the meat dry. Frozen cooked lobster tails work, though you will need to serve the filling in ramekins or scallop shells if there are no shells.
What can I use instead of white wine?
Use 50ml of fish stock with a squeeze of lemon juice. Classic recipes also add a splash of brandy and some tarragon, which you can stir in with the parsley.
Can you make it ahead?
You can make the sauce up to 4 hours ahead, keep it covered in the fridge and warm it gently with the lobster just before filling the shells. Eat any leftovers within 24 hours.
How did you like the recipe?
4.8 / 5 · 44 ratings
