Khanna was born in Amritsar, India to Davinder and Bindu Khanna. He was born with misaligned feet and wasn't able to run until he was 13. He was inspired by his grandmother who loved to cook, and her kitchen became a part of his foundational training. He has an elder brother, Nishant Khanna, and a younger sister, Radhika Khanna.
Khanna began developing recipes at a very young age and opened Lawrence Gardens Banquets to host weddings and family functions when he was 17.
He graduated from the Welcomgroup Graduate School of Hotel Administration from Manipal in 1991, and established SAANCH, a cultural festival gala, to bring together various foods and traditions from different parts of India. This festival has been an important event in the college's calendar.