I'm June visited Chennai Central Station there is Anand Adyar Bhavan and Madras Filter Coffee outlets in PF 7-10 terminal. U can have food there by standing or can takeaway which is the best option. Fares are reasonable for the quantity provided and tastes as the same as their city outlets. IRCTC food stall is also located on opp side to Madras filter coffee. I am attaching him the menu rate card of Anand Adyar Bhavan