Hi Silver 
yeah you have to mix it in later …
I hope it turns out nice … please ensure that the mixture is dry , otherwise you might have issues with kababs remaining intact .. toot jatay hein when the mixture is loose ..
also , I sometimes add imli in the kabab mix and it totally rocks .. just a little imli soaked in water , then drain the water as much as you can and mix the fibre into the kabab mix…