Le Clerc grew up in the Auckland suburb of Westmere. Her mother Loraine made and iced wedding cakes as a cottage industry, and Le Clerc showed an early interest in food. After some years traveling overseas and exploring new cuisines, Le Clerc returned to Auckland and took lessons at the Cordon Bleu school in Parnell. She was soon asked to teach at the institute, and she also opened a catering company.
Le Clerc opened her first cafe with her sister Helen, called Byzantium, and located on Auckland's Ponsonby Road. Her second cafe was the Garnet Road Food Store, in Westmere, just along the road from where she grew up. She then left the cafe business to work on developing recipes and writing cookbooks. She has written for Cuisine, Viva, Next magazine, and the NZ Woman's Weekly, and has had her own magazine. Le Clerc has published 15 cookbooks. She has also presented TV3's cooking show Cafe Secrets for two seasons. Le Clerc holds cooking shows and demonstrations throughout New Zealand, particularly with The Food Show, which is an annual event staged in Auckland, Wellington and Christchurch.
In 2016, Le Clerc spent six months in India as a consulting chef to The Lodhi Hotel, New Delhi, returning a year later for another 6 months.