Use a large knife to cut the rock lobster in half lengthways through the head and tail. Refer to note below if you have purchased a live rock lobster. Scoop out and discard the yellow-green tomalley.
Note: If you have purchased live rock lobster, you are going to need to kill it before cooking. A good option to kill the lobster in a humane way is to freeze it for approximately 1 hour before cooking. This puts the lobster to sleep before it dies. Another option which kills the lobster instantly and painlessly is to place the lobster, belly side down onto a chopping board. Place a sharp knife’s point in between the eyes. Plunge the point of the knife in firmly to go all the way through the lobster’s head on the chopping board, then bring the blade down to finish the cut of the head. Cut through the tail so that the lobster is halved lengthways.
Remove the Rock lobster tail meat from the shell by running your knife blade between the meat and the shell. Place the lobster meat onto a chopping board and use a sharp knife to chop into bite-size pieces. Transfer to a plate and refrigerate until ready to use. Set aside the rock lobster shells for the stock.
To make the Rock lobster stock, heat the olive oil in a large pot over medium heat. Add the onion. Cook for 2 minutes, then stir in the carrot and celery. Cook for a further 3-4 minutes or until the onion is soft. Add the rock lobster shells and bay leaf. Cook for 2 minutes, continuously stirring, then add the water, peppercorns and salt to taste. Reduce the heat to low and simmer for 2 hours. Strain through a fine sieve and set aside.
Melt half of the butter in a large, deep-frying pan (or stockpot) over medium heat. Stir in the chopped shallots and cook until softened. Add the zucchini (courgette) and saffron threads. Cook, stirring, for a few minutes until the zucchini has softened. Stir in the rice and after 2 minutes, pour in the white wine. Cook, stirring, until all the liquid has been absorbed.
Add a ladleful of the hot Rock lobster stock, stirring constantly. When the stock has been absorbed, stir in another ladleful. Continue to add ladleful’s of stock, stirring and allowing each ladleful to be absorbed before adding the next until the rice is ‘al dente’ (approximately 15 minutes). Stir the Rock lobster into the risotto over the heat, stirring constantly for 1-2 minutes or until the lobster pieces are cooked through. Discard bay leaf.
Remove the frying pan (or stockpot) from the heat. Stir in the remaining butter – buon appetito.