Delhi Darbar restaurant just outside pf 1. Other good restaurants like Natraj, Gordhan Thal are at a walkable distance (max 10 minutes). They can be see from train when train reaches UDZ. We tried Rajasthan Dal Bati in Natraj Restaurant (2nd floor) and sweet pan (ground floor). It was great. Unfortunately could not try thali (1st floor) or Gordhan Thal restaurant.
Natraj does not serve south indian dishes.