Prepare the live lobster by placing it in the freezer for 30 minutes.
Heat a large pan of water until boiling. Quickly plunge the lobster into the water and cook for eight minutes or until the lobster has turned completely pink. Lift out and drain well. (You can use the lobster broth for a seafood soup.)
Using a large cleaver or knife, chop off the tail and cut into three sections. Pull off the claws. Using the back of the cleaver crack the shell of the claws and all the lobster pieces - this helps to let the sauce seep into the lobster and flavour the meat when cooking. Divide the body of the lobster in half lengthways and then spoon out the brown flesh, if preferred and discard. Chop each half into two pieces.
Put all the ingredients for the sauce in a blender with 7 fl oz lobster broth and whiz until smooth.
Heat a wok over a high heat. Pour in the sauce, add the crabmeat and season to taste with soy sauce. Bring the sauce to a simmer, then toss the lobster pieces into the sauce, mix well and cook for 1-2 minutes. Take off the heat and serve immediately with egg-fried rice.