Gill grew up in Burnpur, West Bengal, India, where she learned to cook from her mother.
When Gill moved to the UK, she began hosting dinner parties for friends, later running cookery classes, which led to her launching her own range of sauces, pickles, chutneys and spice mixes.
She gave cookery demonstrations both in England and further afield, and in September 2013 she opened her first restaurant, Romy's Kitchen.
Gill's style of Indian cooking is very different from that found at the majority of Indian restaurants in the UK. She uses rapeseed oil in the place of ghee where possible, and avoiding the use of unnatural food colourings.
She combines spices and flavours that she grew up with in India with ingredients that she was only introduced to when she moved to the UK, creating dishes such as gurnard cooked in coconut milk, tomatoes, tomato puree, ginger, garlic and her own spice blend; and monkfish marinated in turmeric and lemon juice, then cooked with onions, ginger, garlic, mustard seeds, 5 spice mix paste and her own spices.
Gill demonstrates her cooking at festivals both in the UK and abroad. In the UK, she has given demonstrations at the Foodies Festival, Grand Designs exhibitions and at food and cultural festivals in Abu Dhabi, New York City and other locations.
In addition, she gives talks and cookery demonstrations in schools where she discusses how food is cultivated, the importance of eating with the seasons and the impact of food on the environment.
Gill, along with two other female Indian chefs and Atul Kochhar, gave a demonstration at Kochhar's restaurant, Benares, in November 2012 to raise money for charity, and is an avid fundraiser for charity Frank Water.
Gill has also appeared on BBC Radio Bristol with Laura Rawlings, and has appeared in a video where she taught rugby star Olly Barkley how to cook Indian food.
In May 2014, Romy was heavily involved with the Bristol Food Connections festival: a citywide celebration of local food and drink. Along with other top chefs such as Martin Blunos, Tom Kerridge and Ken Hom, Romy took to the BBC Stars' Kitchen to give live demos of some of her popular recipes.
During the Bristol Food Connections festival, Romy was also a guest on Saturday Live, alongside Jay Rayner and others.
Gill opened her first restaurant, Romy's Kitchen, in Thornbury, South Gloucestershire in September 2013.
In order to open her restaurant, Gill applied to a number of banks for a loan, but was turned down by every one apart from NatWest, providing her with the business loan that she needed to get her restaurant underway, leading her to be featured on the BBC News in a segment about the struggles that entrepreneurs face when trying to raise the necessary funds to start a new, local business.
Gill was appointed Member of the Order of the British Empire (MBE) in the 2016 Birthday Honours for services to the hospitality industry.
Gill lives in Thornbury, South Gloucestershire with her husband and two daughters. She is an active runner.