The Murano chef has made a commitment to send staff from her restaurants to work at London homeless kitchen Refettorio Felix every month after cooking there herself over the summer.
She believes chefs have a 'responsibility' to address the issue of food wastage at a time when the average UK household throws around £500 worth of produce in the bin each year.
Speaking at Food On The Edge (FOTE) in Galway, Hartnett said: "I do feel it’s morally wrong that there are about 8m households in the UK that can’t afford to feed their families on a daily basis but we feel that we can throw away food so readily.
“We need to be able to encourage everyone to eat better, cook better, and shop better.
“We have amazing produce in this country but we also have it quite expensive.
"I do think as chefs we need to look at wider society and our responsibility when it comes to food waste and training. Working with projects like Refettorio Felix is part of what we need to do.”
Refettorio Felix was set up by Massimo Bottura – whose restaurant in Italy topped the World’s 50 Best Restaurants list in 2016 – as part of London Food Month in June, and has remained open ever since.
The kitchen uses surplus food from retailers, wholesalers and producers to create meals for homeless and vulnerable people in London.
Hartnett said cooking at the site was one of the ‘greatest’ things she did over the summer.
“I took some of my chefs and waiters down there and we opened the fridges and literally cooked with waste food, which was brilliant,” said Hartnett.
“As a result I’ve made a commitment to the guys there. Every month some of my chefs go down there and cook for people from waste produce and leftovers that the supermarkets don’t manage to sell, and make a meal.”
She added that chefs could use their platform to raise awareness of the issue at a time when the industry was more visible than ever.
“You can’t open a newspaper of magazine without chefs or food being involved in some way. Do we do it to put bums on seats and fill up restaurant…or is there a greater good out there we could really move people towards?”
Bottura's Food For Soul charity runs similar kitchens in Milan and Rio de Janeiro, and has been approached to open sites in the USA, Montreal and Vatican City.
Also speaking FOTE, ex-Noma chef Matt Orlando said the restaurant industry needed to change the way it spoke about ‘waste cooking’ to encourage the wider public to adopt its message.