Mix one and a half cups of plain flour and a teaspoon of salt with enough water to form the consistency of double cream. You can also add a beaten egg (which I omit for obvious reasons).
Chuck in a couple of handfuls of mixed shredded vegetables (I use red cabbage, wombok, carrot, spring onion and fresh shitake mushrooms, but you can add squid and prawns and whatever else dead beast you fancy).
Coat the bottom of a frypan with a fitted lid (well, any frypan will do, but if you don't have one with a fitted lid you'll need to find a lid from a similar sized vessel to use) with oil (I use rice bran oil, but anything flavourless will do, like peanut or sunflower, but not olive oil) and heat over high flame.
Add batter, even out, cover with lid and cook for 7 or 8 minutes, checking every so often to make sure the bottom is not getting too dark. If it is, turn the heat down. Flip pancake and cook for another 7 or 8 minutes. It generally takes about 15 minutes all up for flour to cook out. Bear in mind I do everything by sight, so if this stuffs up, you can blame my refusal to measure anything.
Anyway, once the pancake is cooked, stick it on a plate and cover liberally with Japanese mayo (I like mixing wasabi in it, so long as it's real wasabi and not that artificial lurid coloured shit), tonkatsu sauce, bonito shavings (which I also omit for obvious reasons, and should be shaved fresh, but if that isn't possible the pre-shaved stuff from Asian grocers is acceptable) and shredded nori.
Wash down with copious amounts of plum wine and/or sake and/or Japanese beer.