You can check out The Brew Room in SDA Market. They have a pretty expansive breakfast spread!
Smoke House Deli in Khan Market and breakfast is served all day as well.
Brew house ,sda market ...
AMA cafe, New Aruna Nagar, New Delhi
Go for All American Diner, Lodhi Road and AMA Cafe, Majnu ka Tila. They serve a good variety for the perfect brekky!