If I had known where you will be staying I would have suggested restaurants conveniently accessible to you. I am giving you a few names that are scattered all over Delhi. You can make your choice
The Garden Restaurant,
Lodi Road, Opp Mausam bhavan
(You may get to taste some dishes made from organic ingredients)
Indian Accent
77, Friends colony West
(Here you may get to taste both Indian and Western dishes)
Mizo Diner,
85, Chaudhary Hukum Chand Marg, Humayunpur, Safdarjung Enclave
(simple - you may get food here that may not cost much)
Oh Calcutta
Ground Floor, Block “E”, American Plaza, International Trade Tower, Nehru Place,
(Mostly Indian dishes)
Bukhara
Diplomatic Enclave, Sadar Patel Marg,
(It could be a bit expensive as it is attached to the ITC hotel)
Olive Bar and Kitchen Restaurant
Kalkadas Marg , Mehrauli
(A place where there is a Bar, They promise Italian food, as well)