If the train you are traveling in does not provide pantry service or if you want to pick up a good restaurant for you dinner or lunch before departure,one can try the following food outlets with my opinion.
1.Refresh fast food-In the station premises exactly in front of pf five and six.Approximate cost is rs 80-100/per person.No sitting arrangements.(Recommended)
2.McDonalds is situated just outside the station.Exit point near pf 1 and just cross the road.(Okay for fast food)
I stayed in Dongri for 2 months and visited most of the Restaurants.
brother can you please tell me where are the retiring rooms at CST?
Also add Pancham Puriwala which is on the opposite side of the station.
One must surely go here for some Lip smacking Puri Choles. Very economical too.
The only negative is the waiting time on weekends.