To segment the crabs, lift the flap under the body with your thumb and pull off the top part of the shell with one hand while holding the body firmly with the other and discard the top shell.
Remove and discard the spongy white gills on either side of the body and rinse out the brown/yellow much and then use a sharp knife to cut each body in half and then that half in half again and crack the claws with a nutcracker.
Put a rack into a electric fry pan (skillet - ours are square) and put water into bottom of the frypan (in the original recipe they used a bamboo steamer in a wok and used a heat proof dish in the steamer), bring the water to the boil.
Meanwhile, place lemon grass on a heatproof plate and place crab on the lemon grass (try to do one layer) and sprinkle with sugar and drizzle with soy sauce and half of the sliced ginger.
Place the plate in the steamer and cook covered for 3 minutes or until crab is just cooked through (the meat will be white rather than transparent when cooked - we found the crabs in Cowell cooked quicker than we were used to in Perth).
Sprinkle with spring onions and remaining ginger and cook a further minute or 2 until spring onion wilts and then remove from heat (to be honest I put all the ginger and spring onions together in the previous step and missed this one cooking the crab for 5 minutes which actually overcooked it).
We just put the plate (or in our case it was 2 plates) in the centre of the table with finger bowls and napkins and everyone helps themselves or put into individual serving bowls and garnish with coriander leaves.