Okonomiyaki is literally "as you like it", a popular dish from Japan. The best way to describe it is like a cross between an omlette and pancake.
It has a batter (the same kind used in Tako-yaki I think), and then they add cabbage and your choice of add ins- my favorites are cheese, mochi and asparagus! Then it is cooked in a round flat shape on a griddle (much like a pancake) and served with BBQ-type sauce, mayonaise, aonori (blue seaweed) and katsuobushi flakes.
These pictures are from our dinner at Chibo restaurant in Ebisu Garden Place in Japan.