Sustainability might just be one of this year's buzzwords, but when it comes to food, the issue's never really been off the table. Just ask Gill Meller, author of award-winning cookbook Gather and group head chef of River Cottage. Originally a restaurant that came to the fore when celebrated chef and sustainability campaigner Hugh Fearnley-Whittingstall appeared on our TV screens in 1998, the enterprise is now made up of a cookery school and three canteens in Bristol, Axminster and Winchester.

But for the month of September, it's finally coming to London, and bringing its hands-on, ethical ethos along with it. Meller tells us what sustainability means to him, and why it's not as hard to be sustainable in a city as you might think it is.

How does your view on sustainability in the food industry affect the way you approach your cooking?

I approach sustainability through a cook's eyes. For most conscientious cooks and chefs, sustainability in food production – in the UK and globally – should be at the forefront of their minds on a day-to-day basis. There's never been a more important time to think about how our food is produced and where it's coming from, and the impact that's having on the environment around us.

I've always had the mentality to cook seasonally and source locally, and we've always been big advocates of that approach at River Cottage. It goes hand-in-hand with sustainability, and in some ways it promotes sustainability without even shouting about it. If we can support the farmers, growers and producers that are working in a sustainable way, then that in turn creates ripples in the pond.

It's so important because – as cooks and chefs – we are setting trends. The public will quite often look to idols in the food world for inspiration to see what they're doing, so it's up to us to lead the way and encourage people to think about sustainability when they're cooking at home.

Gill Meller is the champion of sustainable eating

Photograph by Rene Masi

Why do you think sustainability has suddenly become so important?

In a way, things have come full circle. Pre-war, food production was sustainable. It's only since the industrialisation of food and farming that we've lost a handle on the effects that our modern-day food systems are having on the environment and everything that surrounds it – it's not that sustainable food production has never existed before.

Such is the seriousness of the situation now that we have no option but to realise it's essential that we shop and cook with sustainability in mind, like we used to. We used to grow our own vegetables and herbs and fruit at home; we used to have the space and time to keep a few of our own livestock animals at our home that would feed the family. That way of life can no longer exist for everyone, but that doesn't mean we can't think much more about where our food is coming from and where it's being produced, and support the people who are doing things properly and respectfully.

How do you think sustainable cooking and eating in cities like London differs from that in rural areas?

There's a sense of irony that, when you live in a city, you have easier access to independent shops but you are further removed from where the food comes from. I live quite rurally and although we've got a number of small growers and farmers nearby, they're not necessarily that obvious and you might not know they were there.

From a practical sense, for most people living rurally, it's just easier to do your shopping in the big local supermarkets, whereas people living in the city can be a stone's throw from an independent retailer who has an ethical, sustainable range of really good produce that's available seven days a week, even though they might be less in tune with the environment.

How have attitudes changed since you started, and what part have you, Hugh [Fearnley-Whittingstall] and the River Cottage played in that?

It's in the last decade that we've seen the biggest change in mindset across the hospitality sector. River Cottage has always been an advocate for sustainable living and we've always been true to that, but even in that relatively short time, things have changed: views have been tweaked and honed; approaches have been shaped to allow for changes in mindset and legislation. For example, back then we were using fish that we quite possibly wouldn't use now because we're much more aware of changes in the fisheries. When I started at River Cottage we would occasionally use eel, but within four or five years we'd stopped using it entirely because ultimately it wasn't a sustainable option for our menus.

You gradually change the way you behave in any environment, depending on the wider circumstances. More recently, we're cooking and eating more veg than we used to at River Cottage, and promoting the fact that we should be eating a veg-heavy diet.

it'll be better for the planet if we eat a more plant-based diet

Are vegetarianism and veg-focused cooking the way forward?

I'm not an expert, but from a cook's point of view it'll certainly be better for the planet if we're eating much more fruit and vegetables and have a predominantly plant-based diet. It's been proven that we can't continue to eat meat at the rate we are, because there's just not the land globally to produce it at the level we are consuming it, so we have to change our eating habits anyway, no matter what. And the only way we could scale up our meat production is by further intensifying the process, which has all sorts of ethical questions that we'd need to confront.

Aside from all the benefits for the land, why should people try to eat more sustainably?

It boils down to what ingredients you consider to be sustainable. If we were to say that most plants grown organically or without the uses of fertilizers and pesticides and so forth can be considered sustainable, you could say that the benefits are not only being felt by the environment but by the producer, by the grower, by the farmer, and by the community in the area in which that food is being produced as well. Then, of course, if you're eating a diet that's sustainable it's more than likely it'll be healthy so you'll be benefiting from a nutritional point of view, and from a general health point of view. You and your family will be benefiting from the effects of sustainable shopping and eating. It's hard to find a downside.

River Cottage at Borough

Throughout September, a series of River Cottage-style cookery masterclasses, free talks and events will take place at Borough Market – a partnership that will celebrate both establishments' approach to produce.

Gill will be hosting a nose-to-tail cookery class designed to show guests how to make the most of lesser-known cuts of meat, and embrace the nose-to-tail philosophy across the breadth of their cooking, including vegetables and salad. He'll also be holding a workshop inspired by his stunning debut cookbook Gather (which came out in 2016), that'll showcase alternative ways to source the best-quality produce. Elsewhere, on 21 September, Hugh Fearnley-Whittingstall will be hosting a vegetable feast created by River Cottage head chef Gelf Anderson made with produce from some of the market's stalls.

Find out more at rivercottage.net

What advice can you offer for people who are looking to cook more sustainably at home?

It's possible to get your food directly from the source. If you do that, you eradicate the middle men and as a direct result the farmer or the producer gets the best possible price for their produce. That's the ideal scenario but it's obviously not something that happens all the time, although you can at least do some of your shopping in that way. It might be as simple as going to a farmer's market and actually meeting the producer and farmer and talking about their ingredients and taking them home with you. The farmer is getting the best possible price for their stuff and you're getting, more often than not, the freshest produce in the best condition from a place you have confidence in. It might be as simple as picking up some eggs from a farm gate sale. Whatever it is, a little goes a long way. There's a lot to be said even for supporting your local greengrocer or the local butcher.

If you enjoy food and cooking at home, then ultimately the best advice I can give you is to cook seasonally. Find out what's at its best at any one time, get out there and find it locally and treat the ingredients simply. If you're cooking with great fresh stuff you don't have to overcomplicate things. Think about how much you buy and don't overspend and don't be wasteful. One of the major ways that we can contribute to having a sustainable food system at home is by minimising how much waste we produce. It's rewarding – and that's the way cooking should be.

Feeling inspired? Get more sustainability tips here.