You can use your favorite ingredients when making Okonomiyaki, plus the basic ingredients: cabbage, flour, water and eggs. For our Okonomiyaki we chose prawns, bacon (instead of thinly sliced pork) and green onions.
And that's how the 'dough' looked like:

If u don't call a real Teppan your own (like us, unfortunately), you can also use a pan.

Doesn't look really tasty yet, right? XD

The finished Okonomiyaki get coated with japanese worcestershiresauce (Soosu) and mayonnaise, and sprinkled with Bonitoflakes (Fish Flakes)^-^
This was the first time I made them myself and I was really impressed how authentic they tasted, compared to those I ate in Tokyo.