Heat the mirin, soy sauce, worcestershire, agave and vinegar in a small saucepan over medium heat until it comes to a small boil.
Reduce the heat and whisk in the palm sugar and xantham gum until dissolved. Remove from the heat and set aside to cool. (It will become thicker as it cools.)
To make the pancake
Combine the flour, baking powder and salt in a large bowl.
In a smaller separate bowl, whisk together the soymilk, Ener-G and cider vinegar and let it sit for about 5 minutes to slightly thicken. Then slowly add the liquid into the flour mixture and mix gently until combined. Do not overmix.
Add in the vegetables and gently combine again with the batter. Set aside.
To make the okonomiyaki
Heat a flat non-stick pan over medium high heat. Once it is preheated, spray it with a bit of cooking spray. I used a flat-bottomed 3/4 measuring cup to scoop out the batter and slowly pour it onto the pan. Then I kind of flattened the pancake out using the bottom of the measuring cup.
Cook for about four minutes on each side or until golden brown. Serve immediately with the sauce. This also tastes great with Vegenaise on the side.