Okonomiyaki is made in Osaka and Wakayama with cabbage, pork, eggs, green onions and okonomiyaki flour that has the consistency of pancake batter. It's put on the grill then topped with mayo, furikake, okonomiyaki sauce (similar to tonkatsu sauce, just a little sweeter), and bonito flakes on top.
Hiroshima style okonomiyaki is served with yakisoba noodles. Unfortunately, I'm not sure how to make this from scratch, so either get the okonomiyaki mix and add cabbage, egg, protein and green onions, or use the okonomiyaki flour.
We learned that if the protein is not cut thin enough (in this case, we used belly pork sliced by the butcher), then the meat has to be cooked on the side and added later. I like it without the pork. For me, the key is the bonito, mayo, sauce and furikake. Another thing, when frying the okonomiyaki, let it get crispy for a nice texture in your mouth. :-)