Rock Lobster Thermidor

Recipes | Baking Serves 2 Rock Lobster Thermidor

This is a simplified version of the traditional Lobster recipe. If time is short, buy a ready-cooked rock lobster and gently warm the meat in the sauce before spooning into the shell.


1 x 1kg live Rock Lobster (see notes) 
½ cup fish stock
½ cup dry white wine
75g cold butter, cubed
2 golden shallots, finely chopped
3 tablespoons plain flour
½ cup milk
¼ cup cream
1 teaspoon English mustard
Salt flakes and freshly ground white pepper, to taste
1 tablespoon finely chopped chervil or chives
2 teaspoons finely chopped French tarragon or dill
¼ cup (20g) grated gruyere cheese


Bring a large saucepan of well-salted water to a rapid boil. Plunge chilled Rock Lobster into the water (see notes). Cover until it returns to the boil, continue boiling for 13 minutes, then remove and refresh in iced water.

Meanwhile, combine fish stock and white wine in a small saucepan and boil until reduced by half.

Melt one third of the butter in a separate saucepan and cook shallot over low heat until soft. Stir in flour and cook for a few minutes until light golden. Add milk and cream and whisk constantly until sauce boils and thickens. Whisk reduced stock, mustard salt and pepper into the white sauce, whisking constantly until sauce boils and thickens. Remove from heat.

Split Rock Lobster in half, clean, remove flesh from shell and cut into large cubes. Set meat and shell aside.

Preheat overhead grill to high.

Return sauce to a low heat and stir until hot. Whisk remaining butter into sauce, piece by piece, and stir herbs through. 

Pour a little sauce into the two halves of the Rock Lobster shell, stir the meat through the remaining sauce and spoon into shells, sprinkle grated cheese over the top and place under grill for 3-4 minutes until golden brown.

Serve with a green salad on the side.


The easiest and most humane way to kill any crustacean is to chill them in the freezer for 30-60 minutes until they become insensible (but not long enough to freeze them). Once chilled, they should be killed promptly by splitting in half. See NSW Department of Primary Industries or RSPCA for more details.

Alternative species:

Large Marron (reduce boiling time to 1 minute per 60g average body weight).

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