There are so many...to name a few -
Lunch - fine dining
Shahi Maharani Restaurant @ Raffles City
Dinner - Reasonably good food @ S$10 (not sure if they have lunch buffet)
Sagar Ratna Opp Mustafa
Masala Art (basement of Peninsula, next to Komala's)
Lunch @ S$19 ++. Dinner @ S$26 ++
Cheers !
Parag