By Dana Rose Falcone
May 12, 2015 at 04:59 PM EDT
Dimitrios Kambouris/Getty Images

TV chef and author Sandra Lee recently learned she has breast cancer, she announced on Good Morning America Tuesday. The call came while Lee finished a photo shoot for People‘s Most Beautiful issue on March 27.

“I was still,” Lee told GMA host Robin Roberts. “I didn’t even cry. I was stunned.”

Lee has already undergone a lumpectomy and is preparing for her second surgery. She said her partner, New York State governor Andrew Cuomo, has been “extremely supportive” and will be with her in the operating room.

The celebrity chef, 48, feels lucky to have began mammogram testing when she did, as the doctors told her they caught the cancer early. Still, Lee won’t let the sickness dominate her.

“It beats up your body and it beats you up emotionally,” Lee said. “I wasn’t going to let it rob me of one day of happiness.”

Head to People for more on Lee’s fight against breast cancer.