Food waste is endemic at every stage of the supply chain - from grower to market to kitchen.
The statistics are grim: one-third of food produced for human consumption is lost or wasted globally - approximately 1.3 billion tonnes per year.
Food production puts a huge strain on the world's resources; rotting food in landfill produces methane, a greenhouse gas.
We can all play our part in reducing waste. (See here for our profile on City Harvest, a charity rescuing food waste from the Market.)
Here are chefs' top tips - from using new technology to recycling onion skins and getting nifty with the dehydrator.
Not all plants are equal
'Root to flower' is a phrase coined by Vernon Mascarenhas of Nature's Choice, a catering supply company on the market. He has spent decades encouraging growers and chefs to develop a holistic view of the ingredients - using parts of the plant often chucked into the bin.
"For example, I encourage chefs to use purple sprouting rather than calabrese [broccoli]," says Mascarenhas.
"If you harvest it properly, snap it off properly, then the plant regrows. With calabrese, you only get one head from all that space of land ... the amount of food we produce per square foot is very important."
Over the years, he has helped to introduce a range of new ingredients such as cucumber flowers and broad bean flowers. He talks directly to growers: "Can you put that broad bean flower in a punnet rather than drop it on the floor?" Mascarenhas says he took the first punnet straight into Nobu, a restaurant on Park Lane.
Measure your waste
"The best piece of advice I can give to chefs is to simply look into their bin," says chef Anne-Cécile Degenne. Analyse exactly what is getting thrown away and in what volumes.
To take this to the next level, technology such as Winnow may help. We first encountered this during a visit to Lamberts Restaurant in 2014 - who get their fruit and veg from the Market. (See profile here).
Winnow is a simple touch-screen computer system that lets you keep track of exactly what you throw away.
"If you make a significant reduction in your waste by definition you make a significant reduction in your costs – and who in the restaurant business doesn’t want to do that?" says food waste campaigner and Winnow customer Hugh Fearnley-Whittingstall.
Lemons and oranges
Chef Mark Broadbent is a big fan of using lemon leaves: "The leaves are amazing and pungent ... You can marinate chicken with lemon leaves, garlic and thyme. You don't get any acidulation this way. Lemon zest can be a bit overbearing."
Chef Tom Hunt (his Instagram is here) recommends using the leftover skins of oranges and lemons when roasting meat. For example, put a bed of vegetables and lemons on a wire rack / trivet under the meat. Obviously, orange and lemon skins can also be used to make a marmalade.
Pea pods have all the flavour of a pea. Use them for a stock, perhaps for a pea risotto. Chef Skye Gyngell of Spring at Somerset House serves them in a juice, washing the pods then pushing them through a juicer. The liquid is mixed with a dash of lovage or elderflower cordial and lemon juice, then served over ice topped up with sparkling water and a sprinkle of celery salt.
Chef Mark Broadbent adds shallot skins to chicken stock when he wants a golden colour. At Parlour, a restaurant run by chef Jesse Dunford Wood, they serve a dish of 'Attenborough's Neolithic Egg': eggs boiled for seven minutes then refreshed in ice water and cracked all over. These are then left to steep overnight in a tea of onion skin water. "The dye seeps through the cracks and when you peel it it looks like a dinosaur egg."
Cauliflower and broccoli
"Everyone always eats the top of the broccoli and guess what? The stem tastes just the same," says Dunford Wood. "The same is true for cauliflower." His team shaves the stems down and then cuts them in a julienne. The leaves are cut in a chiffonade. Hunt recommends using the florets and leaves for his take on kimchi. You can also cook the leaves on the grill or barbecue, dunking in water first and using a lid to steam as you cook.
Use the stalks and skins to make purees, stocks and sauces, says Dunford Wood. He also dehydrates them to make a mushroom powder. "It's very trendy these days to sprinkle [powders] on plates."
The peelings can be dipped in rice flower then deep fried. At Fearnley-Whittingstall's River Cottage restaurant they then dust them with sugar and cinnamon to serve with desserts.
Purees are also an excellent way to use the peelings of parsnips, carrots and other veg.
Beetroot and radish leaves
At Gyngell's restaurant they offer a 'Scratch' menu from 5:30 to 6:30 pm using leftovers. This might feature dishes such as slow cooked beetroot leaves on bruschetta with wet garlic and ricotta. Beetroot leaves are also excellent wilted into curries.
Jamie Oliver adds radish leaves to his Moorish Crunch Salad, with carrots, apple, mint and parsley.
Composting and rescue recipes
"That's what gets my goat - people not composting their waste," says Hunt. It is easy to overlook the fact that food waste in landfill is a major contributor to greenhouse gases, producing methane - a particularly pernicious pollutant.
Hunt advises putting in place strategies for separating and managing waste streams. One tip is creating 'rescue recipes' for ingredients often thrown away. "This means the excess produce is repurposed and used in another dish."
Food waste has become a more high profile issue than ever. With global supply chains stretching many thousands of miles - from grower to the caterers - it's also a complex problem with no easy answer. But these are a few ideas to inspire you to make the most of every part of your produce. Let us know if you've got any more tips.