Author Sarah Wilson is a passionate anti-waste warrior. A long-time crusader for secondary cuts of meat, eating your daggy vegetables and encouraging energy-efficient slow-cooking, she has shone the spotlight on sustainable eating (admittedly camouflaged behind Instagrammable recipes).

With consumers apparently throwing out up to 50 per cent of their groceries every week, Sarah takes food wastage pretty seriously.

“Recycling and composting just doesn’t cut it,” she says. “Not buying and wasting in the first place does. That is using what we have, cooking our leftovers, eating the whole food – pith, peel, stalks, stems, leaves, bones, brine, fat, skin and all. This is the future.”

Here are some of Sarah’s favourite tricks for elevating leftovers to the main attraction.

Whittling your waste at home

When grocery shopping, Sarah recommends you buy discounted perishable items, such as meat and hard cheese, and either eat them straight away or freeze for later use instead of binning them.

She also suggests you look for imperfect vegetables that would otherwise be thrown out, as they are usually cheaper – though no less nutritious – than their perfect peers. And finally, use your scraps creatively.

Sarah says, “I keep all the peels, leaves, stalks, off cuts, bones and other leftovers in bags or containers, ready to turn into stocks, smoothies and pestos. If I don’t have time to make something straight away, I whack the bags in the freezer.”

How to eat out without throwing out

Sarah’s endeavours to limit food waste extend to eating out. They include retrieving sardine heads left over from a book shoot to turn into a pizza topper for dinner, to asking strangers at the restaurant table next to her if she could take home their leftover Angus beef strips (which she transformed into a Vietnamese soup).

Depending on your level of commitment to the cause, she recommends the following for minimising food waste while dining out.

Don’t order extras until you’ve finished what you already have: While Sarah recommends buying in bulk at home, when eating out it’s better to avoid the temptation to over order. Consuming less is the first stop in avoiding waste, she says.

Ask for a doggie bag: “Get real and responsible”, says Sarah. Scraping together food for seconds isn’t scabby. In fact, it’s the perfect way to get creative and repurpose leftovers for lunch the next day.

Collect your bones: Whether it’s beef, chicken or the carcass of the snapper that you just had for dinner, bones provide the perfect basis for a stock. Pair them with your vegetable scraps for the ultimate in waste-free cooking.