then you have all Al Sadd / Al Nasr options.
Try Shawerma at one of Nasr restaurants...
Al Arabi makes a delicious one, and turkey Central makes great barbecue and delicious Shawerma ...
Maybe MAcdo at Center point?
or even some sandwiches form Take Away Al Sadd, next to Opera?
and there is KFC just in front..

well... I hope this helps