Sumayya was born in Karachi, Pakistan in 1973. She travelled the world on merchant ships with her parents until the age of nine. Sumayya's family finally settled down in Karachi, where she then grew up. Sumayya read for an LLM from University College London in 2001 and practiced law at her father's law firm in Karachi. In 2006 she moved to London and worked as a solicitor in a City law firm until 2012 when she quit law to pursue food writing full time.
Sumayya is passionate about her heritage cuisine and has written two cookbooks on Pakistani cuisine. Her first book, Summers Under the Tamarind Tree: Recipes and Memories from Pakistan (Frances Lincoln, 2016) was the first Pakistani cookbook in Britain and won the Best First Cookbook category in the Gourmand Cookbook Awards in 2016. It was also shortlisted The Edward Stanford Travel Writing Award for Best Food and Travel book 2016. Her second cookbook Mountain Berries and Desert Spice: Sweet Inspirations from the Hunza Valley to the Arabian Sea (Frances Lincoln, 2017) was shortlisted for the Best Cookbook of the Year category Food & Travel Magazine Awards.
Sumayya is now settled in Glasgow, Scotland where she founded Kaleyard Cook School, a social enterprise that focuses on elevating social isolation and bringing people together through the power of cooking and eating together. Sumayya continues to write and teaches cookery full-time.