Thrrread resurrection! :)
As a student in Japan, I can confirm that the carb "miso/guts/mustard" is indeed greatly valued and appreciated in a variety of ways.
Unlike roe though (since some mentioned that semblance), here crab guts are indeed used in a similar way miso is: A flavouring substance, or soup stock base. Do not be alarmed by the thought of slurping gooey grey matter, because chances are you won't (well ok it *is* used as topping in minimal quantities too but that hardly has a texture).
Here are some uses:
-mix with actual miso and form a base for a great broth for kani-suki, kani-chige or similar crab-soup dish. Delish!
-mix into the sauce you made to dip the white crab flesh - great enhancer for the relatively timid steam version (use after steaming - raw guts are usually fine but best minimize that 'usually')!
-add a tiny bit of the guts after steaming on top of pre-cleaned crab flesh and lay over rice. Hokkaido on your table!
-mix (after cooking again) into your home-made tartar sauce for use not only with the late crabs but with all kinds of fish, shrimp and other seafood dishes. For those (like me) who avoid tartar due to the fat overkill, you can make interesting sauces like wafuu (soy-mirin-sake-yuzu), seasame paste+wafuu etc and mix some guts in for flavor!
-add a pinch between the main ingredient and the rice in both nigiri and maki types of sushi. Skip or minimize the wasabi when you do, as its strength would overbear the precious crab essence.
-Seafood salad anyone? Tired of supposed 'seafood' salads that only taste of seafood only when you happen upon an actual bite of it? Mix the steamed/boiled guts into your salad dressing, be it vinegar, olive oil or whatnot, and make it both aromatic and tasty!
-Rissoto! From the rich italian seafood risotto to the famous Madrid paeya, a pinch of crab miso never fails to kick it up a notch. Just don't overdo it, as rice dishes are meant to be light and balanced, and making it too rich might make it feel heavy and stuffy. Can also be similarly used in marinara (which is seafood tomato sauce by the way, a note to US folks since it is wrongly thought to be just a version napolitan in some states - confirmed it myself when I saw a meatball-cheese-marinara sandwhich in a shop in VA and went yuch! - until I found out the mistake there)
-How about a drink then? No no, don't go about putting that stuff in your cocktail of preferance now. But the salty goodness of crab miso goes well with drink-snacks, called otsumami here. Either as part of a snack dipping sauce or actually mixed into vegetable or seafood chunks, it will make you keep on drinking and eating. Just try to stop before it all ends up in an unsightly accident. Tip: A ziplock back with a few drops of good vinegar, the cooked crab guts and optionally some herbs/spices/drops of honey to taste makes for an excellent drink-snack flavouring engine. Stuff the vegs or seafood bits in the bag, zip close, shake, serve. The vinegar also helps preserve the stuff, so this is actually even worth considering for actual bar use.
That's all frm me!
Best regards from a Greek in Kyoto and hope OP or other people interested find these tips useful!
Edited by Kabakuma - 11/8/11 at 2:54pm