Lichen is the surprise new ingredient on fine-dining menus, thanks to our love of Scandinavian and Indian cuisines

Because of the influence of Scandi and Asian cuisine on the UK's dining scene, lichen is having a growth spurt on the nation's menus. "Black stone flower", a lichen also known as "kalpasi" or "dagarful", is a common ingredient in the southern part of India, particularly Hyderabad and Chennai, and cooks from those cities have brought the ingredient with them to the UK. So whether you realise it or not, you've probably already tried some lichen at your local takeaway. The UK's Scandi-style restaurants have also picked up on the trend for using foraged ingredients from the likes of René Redzepi's Noma in Copenhagen, which regularly serves moss with cep mushrooms. Sat Bains in Nottingham now has roe deer with mushrooms and lichen on its tasting menu, at L'Enclume in Cumbria restaurateur Simon Rogan serves deep-fried lichen as a snack, and Kevin Tickle, the head chef at Rogan & Co in Cartmel, uses Reindeer Moss (which is not a moss at all, but a lichen) in a savoury mushroom dish, with roasted ox tongue and smoked bone marrow.

The taste varies depending on the genus you're chewing and the way you prepare it, according to Dr Thus, who is also the senior curator of lichens and myxogastria (slime moulds) at the Natural History Museum. It's an acquired taste, but not unpleasant, rather like truffles. "Many lichens have a mushroomy flavour; a bitter note; some sharpness," he says.

Unsurprisingly, the dead reindeer preparation method is not unanimously loved. The traditional native American way to make lichen palatable is to soak Wila – a brown lichen resembling straggly tree roots – overnight, then cook it on hot rocks in a pit in the ground. It's still used in Aquavit today, rendering the Scandinavian spirit almost tasty.

Lichen is just one of a range of ingredients Vivek Singh uses in his cooking (Justin Sutcliffe/The Independent)
Home cooks might prefer to shun these time-tested procedures in favour of Vivek Singh's far simpler method of preparing lichen: buy it in dried form, stick it in a pot – et voila! Healthy, nutritious lichen – well, almost.

The jovial executive chef and CEO of the Cinnamon restaurants meets me at one of his restaurants near London's Liverpool Street to cook two dishes with "black stone flower", a lichen also known as "kalpasi" or "dagarful", which forms part of the restaurant's special menu, served for special occasions, such as Holi last month. Black stone flower is a common ingredient in the southern part of India, particularly Hyderabad and Chennai.

"When you first start as a novice, you never come across these ingredients," says Singh, as he puts the earthy-smelling "flower" into a muslin bag with cinnamon sticks and cardamom. "When you get to a very high level, the cooks will let you into their secrets and that's when I came across lichen. It's not a high-street spice – it's the next level up."

It turns out lichen is a very "cheffy" ingredient. You might not find it in your local supermarket, but if you look hard enough, you'll find it on fine-dining menus. Rick Stein recommends lichen in his book and TV series Rick Stein's India and The Fat Duck serves Oak Moss (which is not a moss but a lichen called Evernia prunastri) with truffle toast, jelly of quail, crayfish cream and chicken liver parfait.

The Ethicurean restaurant in Bristol, which specialises in locally sourced ingredients, regularly uses Oak Moss and Reindeer Moss in its food and drink.

Vivek Singh, founder of the Cinnamon Club, demonstrates the uses for lichen in subcontinent cuisine (Justin Sutcliffe/The Independent)
"We shallow fry the Reindeer Moss with a little bit of tonka bean, which has a vanilla, almost truffley flavour," says Matthew Pennington, head chef. "It does make a good garnish and we use it occasionally on our roe deer dish. Oak Moss is an inherently beautiful thing. It tastes like an oriental leaf and the taste is quite separate from the scent, which is evocative of woodland."

It's best to get lichen from organic food suppliers, specialist foraged-food websites, or Asian supermarkets rather than foraging for your own lichen because, aside from the risk that it has absorbed pollutants, it's also easy to mis-identify and many UK species are protected, so you'd be breaking the law if you picked the wrong kind. Even though Pennington has an understanding of the organism, The Ethicurean's lichen is collected by an expert forager. "It's a subject, as with mushrooms, where you need a bit of knowledge, because you can give yourself a bit of a stomach ache otherwise," he says.

Back in the Cinnamon kitchen, Singh smooshes garlic and ginger paste onto a slab of lamb, which he then slices into strips, while steam rises from a sturdy pot of gravy where lamb stock, tomatoes, onions and that tightly-wrapped muslin package are stewing away.

Lichen is symbiotic; it's a fusion of fungi and algae, and in the same way that it binds things together in nature, it does the same with flavours in food. Singh describes it as a "flavour fixer".

Lamb, rubbed with a dry roasted spice mix including lichen, then grilled and served with coriander chutney and raita (Justin Sutcliffe/The Independent)
We dry fry the spices, opening up the aromas; cumin seeds, cardamom seeds, cinnamon, allspice, peppercorns and cloves. Lastly, we sprinkle in the fragile little lichen spores.

"It won't taste very nice just like this but it smells heavenly," says Singh with a hearty laugh. He's clearly enjoying this.

He hands me an important-looking pestle and mortar (it's heavy and golden) and I beat the spices and lichen, which crunches, then we add oil and coat the meat. Singh flash fries it on a really hot barbecue-type grill, called a pattur ghosh (meat stone), "but you can use a griddle pan," he says.

In just a few minutes, the colourful kebab is ready. Singh serves it straight from the grill with minimal fuss, dollops of coriander chutney and smoked paprika raita. But there are so many different spices in the meat marinade and stock, it's difficult to determine which bit is the lichen flavour.

"You will be able to detect a fragrance that is different from cloves or cardamom or any of the spices we've used," says Singh.

"You should sense a bit of that fragrance but also you should feel the blending in of one flavour into the other."

It tastes wonderful. The flavours are in harmony. The dish is warming and comforting.

"Yes. It's not just the individual instruments playing their sound," explains Singh, "it's actually the symphony coming together in an orchestra, so the lichen, in a sense, is a conductor." Play on, I say.

Vivek Singh prepares the lamb, rubbed with a dry roasted spice mix including lichen (Justin Sutcliffe/The Independent)
Bhaditraka (Lamb kebab)

Ingredients to serve 4

400g prime cut of lamb leg or a whole thigh
1 tablespoon ginger paste
1 tablespoon garlic paste
1 medium onion fried till golden brown
6 green chillies
1 tablespoon of mint chopped
1 tablespoon of fresh coriander chopped
Juice from half a lemon
2 tablespoon of vegetable oil
1 teaspoon papaya paste (optional)

For the spice mix

Roast the following spices and pound to a coarse mixture

1 tablespoon cumin seeds
4 black cardamom seeds
1in cinnamon stick
1 tablespoon all spice
1 tablespoon peppercorns
2 tablespoons cloves
5-7 sprigs of black stone flower/rock moss

Method

Trim off the excess fat from the leg of lamb. Debone it and clear it off from any sinews. Using a sharp knife.

Slice through the meat and prepare neat escalopes. In a mixing bowl, take the lamb and marinate with all the ingredients. Rest for at  least 2 hours.

Sear the lamb escalope in a very hot pan for about 30 seconds on each side and rest for a minute before serving.

This dish is ideal if you have a barbecue grill available, as it can benefit from its smoky flavours.