Okonomiyaki is a mixture between pancake and pizza. "Okonomi" means "as you like". This refers to the ingredients.
Cut four large, green cabbage leaves without the hard, white core in thin strings (ca. 4 mm).
Mix the water, flour, eggs and the cabbage strings together.
You may now add more ingredients to the dough: e.g. seafood, cut in little pieces, ground meat, cut mushrooms, etc.
Fry the dough like a pancake in a small frying pan.
Before turning the okonomiyaki over, and while the dough is still quite soft, you may put other ingredients on top of the dough.
Turn the okonomiyaki.
When fried well, serve the okonomiyaki with katsuobushi, aonori, mayonnaise and okonomiyaki sauce.