Paul Foster's Tuddenham Mill: River cafe

The chef's award-winning menu is inspired by plants gathered in the waterways around his Suffolk restaurant. He shows Jamie Merrill the riches of the riverbank

If you walk along one of the small tributaries of the river Lark in west Suffolk on a sunny afternoon you might just catch a glimpse of Paul Foster combing the riverbank, occasionally stopping to inspect a bush or weed before taking a precise cutting. Foster isn't a botanist though, he's the head chef at Tuddenham Mill hotel and restaurant and he's foraging for his patrons' supper.

Foraging is hardly new. Nettle soup was a staple for many living the Good Life lifestyle in the 1970s, but more recently, thanks to the efforts of Jamie Oliver, Hugh Fearnley-Whittingstall and superstar chef René Redzepi, whose commitment to wild food helped his Copenhagen restaurant Noma pick up the title of the "best restaurant in the world", more and more people have attacked Britain's rural hedgerows in search of free wild food.

Foster, 29, who brought his style of cooking to the heats of Great British Menu on BBC 2 earlier this year, who was nominated Up and Coming Chef of the Year by The Good Food Guide and was named Young Chef of the Year, by Observer Food Monthly, isn't just jumping on the bandwagon, though: "I know a lot of foodies see foraging as a passing trend... but for me it's not about making a song and dance about it for six months then forgetting about it."

He previously worked at Michelin-starred establishments including Restaurant Sat Bains in Nottingham, The French Laundry in California and Raymond Blanc's Le Manoir Aux Quat' Saisons near Oxford. Now with Tuddenham Mill's 12 acres of riverbank and water meadows as his "larder", Foster's menu includes mugwort, ribwort, meadowsweet, wild watercress, wild garlic, bulrush stems, wild asparagus and other plants found by or near the water. You'll have to work hard to spot them on the menu though.

"I like to let the tastes and textures do the talking, so I don't make a big deal of my foraged ingredients on the menu," says the young chef. "For example, I have hake and confit potato on the menu, but it doesn't say that it contains chickweed [which tastes like spinach when cooked] from the water meadow. It's there for its flavour, not because I want to say I use foraged food."

Joining Foster last month, it's clear he's excited about foraged food, though. He tells me he spotted a wild asparagus bush earlier in the year and we work our way along the riverbank and through the meadow to see if it has yielded a stem or two. On the way he explains that there are more ingredients in the meadow than he could ever use, including meadowsweet, elderflower, mugwort, wild asparagus, wild garlic, yarrow, bulrush and ribwort. "They love the moist soil," he says.

It was while working for Sat Bains as a sous chef that he first started using foraged ingredients. Since then he's worked with Miles Irving, the author of The Foraging Handbook, at Tuddenham Mill, and Irving still supplies some of the wild ingredients he can't track down locally. "Just like Miles I'm very particular about what I pick and where I pick it," says Foster.

"And if I'm unsure about something I'll send him a photo or drop him a call to check before it ends up in my kitchen and on the menu." As a general rule, foragers should consult a reliable book and ideally take part in a professionally led foraging walk before they try anything more adventurous than nettles and elderflower. On Irving's advice Foster also recommends picking only the leaves and stems and always seek permission from the landowner if you're not foraging on common land or public footpaths. It's also illegal to forage on sites of special scientific interest without a special permit.

For riverside foraging in particular, Foster explains, "it's important to make sure that there is clear running water and never forage anywhere if there is an eggy smell or boggy stench." Others do sound a further note of caution, though.

"You can look at foraging in two ways," says Fergus Drennan, one of the UK's leading foragers. "Most foragers have innate environmental concerns, some plants such as nettles and elderflower are abundant and foraging helps spread the word about protecting habitats from development, but there's a tension between foraging for personal consumption and to supply restaurants.

"As we know, the publicity from René Redzepi and other chefs means foraging is still ballistic right now and every restaurant that thinks it's half-decent wants to have foraged ingredients on the menu, which is going to put potential stresses on wild populations of plants."

Drennan points to the example of sea kale, which was almost foraged to local extinction by Victorian restaurants in 19th-century Whitstable and instead recommends a smaller-scale and more sustainable form of foraging. "Ultimately my gut feeling is that it is an environmental dead end to supply restaurants, but I admit it's not that simple. It's an area that could really do with some proper academic study to see what foraging is doing to biodiversity in the countryside."

Foster is aware he has a limited resource and takes a common-sense attitude to what he picks and what he leaves behind. On the way to the possible wild asparagus spot we stop for Foster to pick a few stems of mugwort from the riverbank. It has a musty and minty aroma and Foster will use it to replace mint later.

"I try and use foraged materials when they are in season to replace bought-in ingredients," he says.

He spots some ribwort plantain and puts it in his basket. "So when I can find meadowsweet, I use it to replace vanilla, while ground ivy replaces sage for some of the year. By matching flavour profiles I can then match them to ingredients I know they will work with." Reaching the wild asparagus means a scramble through some bushes and working our way across a stream. Sure enough, there, standing alone is one thick asparagus stem. It's like he's planned it, but Foster jokingly assures me he didn't plant it there for my benefit and it goes into his basket for later.

Now there's only a quick stop at the hotel's pond to pull up a few bulrush stems. Back in the hotel's kitchen Foster lays out his ingredients and sets to work on a mini menu for me. First off is a 40C poached salmon with a salad of mugwort fresh from our scavenging trip, sheep sorrel, chickweed flowers and watercress with shavings of wild asparagus. The flavours are light, but also peppery at times, which Foster tells me is the sorrel coming through. It's all very fresh, so doesn't overpower the salmon. This is followed by what on the evening menu appears simply as "West Country lamb, wild garlic and yoghurt".

To this seemingly simple dish Foster adds bulrush slices – from deep inside the stem and soaked in warm butter – and a yarrow garnish for the yoghurt. And somehow the strength of the lamb doesn't drown out the delicate – slightly nutty with a hint of cucumber – flavour of the bulrush. It's a triumph and with customers lining up to speak to Foster as I leave, you can see why he's is seen as such an up-and-coming young chef.

The awards haven't gone to his head though: "Lots of people have jumped on the foraging trend and ended up bastardising it. They are forgetting that you need to respect every ingredient and make it fight for its place on the plate. There's no point just chucking something on because it's foraged." At Tuddenham Mill at least, this is a trend that's not going away any time soon.

Foods to find

In town

It might seem unlikely but there are some great foraging opportunities in town. Pineapple weed, which looks like chamomile without petals, grows in the cracks of pavements and tastes just as its name suggests. Ideal to infuse into ice cream, it can also be made into a tea.

In the country

The best place to start is with nettles for soup. And there's more to elderflower (it's everywhere this time of year) than cordial. It is great in cocktails but can also be used in creamy puddings such as pannacotta. Beyond that, a good foraging book is essential.

By the sea

One of the sweetest tangy delights – best between September and December when they are vibrant orange – is sea buckthorn. Its berries, found in scrubland near sand dunes on the scrub-like buckthorn tree, work well in cheesecake when reduced to syrup.

For recipes visit wildmanwildfood.com