On the San Francisco board Sushi Monster was wondering how to best treat our local San Francisco crabs...here goes:
Some people like to clean crabs before they're cooked to avoid letting the viscera flavor the meat; this is not a problem if you steam them.
This is how I like to do it, following Melanie Wong's suggestion ( http://www.chowhound.com/topics/show/... ) to steam them upside-down to preserve the crab butter.
1. (optional) Buy yourself a good bottle of white truffle oil. A little goes a long way, so get the smallest highest quality jar you can find.
2. Buy some live and snapping crabs from your nearest good Chinese market or docks; the Chinese markets in San Francisco tend to be cheaper than the docks and only mark up ~30% above wholesale. They're very competitive, and keep them live in cold water tanks.
3. If you have a colander or other object you can use to steam the crabs above boiling water, toss that in your pot to heat. Otherwise just put in less than 1 inch of water so the crabs don't get waterlogged.
4. Cook one crab at a time for large crabs, so they can lay flat on their backs in the pot.
5. Cook at least 10 minutes, up to 17 minutes depending on the size of the crab.
6. If you're impatient, remove and rinse under cold water until just cool enough to handle
7. Using a heavy duty chef's knife (not your thinnest lightest sharpest knife) to butcher the crab:
a) I start by cutting through the mouth area; if you're looking at the underside of the crab, I cut just in front of the pair of legs with claws, around 1" from the front edge of the shell; no need to go all the way through, just cut the underside. The smallest legs attach near the back edge of the shell, and after cutting the front end I stick the knife between the shell and the small back legs and twist to pop the legs with meat up and out of the shell.
b) Resist the urge to throw away the bottom shell
c) Rinse the viscera from the middle section of the body under running water; split the crab in half down the middle and finish rinsing any cavities.
d) If you slightly undercooked the crab or feel you got too much cold water in it, return the halves with meat to the steamer to warm and let water drain from the body; arrange the halves with the broken side down and the legs up.
e) Look for crab butter. There are a few pockets of crab butter which have probably melted by now, but the inside surface of the carapace should be lined with 1/4 inch of clean looking white fat, the consistency of a barely solid pana cota. Scoop this out with a spoon while avoiding bits of organs that should remain; flavor gently with drops of truffle oil. I didn't heat mine until it melted and had no gastro problems, but if you aren't sure of your crab's freshness heating the crab butter to 160 should kill anything that could possibly be in it.
8. Ravenously pick and eat your first crab after putting your second crab in the pot. This will allow you to pick the next crab clean for more civilized dining in sandwich or salad form.
9. Repeat with a second crab; drizzle truffled crab butter over the meat or spread it on toasted brioche, squeeze with lemon, add avocado if you're in the mood, and enjoy.