“It’s a philosophy of life. It’s happiness,” says Mathieu standing in a forest clearing in early May, basket in hand. Clearly at home in nature, the Belgian chef picks a few leaves from a plant: “This tastes like a very sour Granny Smith apple,” he says. And indeed, it does. Another leaf could fool you into thinking you’re having champignons de Paris.

The abundance of the forest for Mathieu is seemingly endless. Where a proverbial greenhorn sees mostly foliage and flowers, Mathieu sees flavours and textures. He knows the area around the château like the back of his hand.

Nestled between tall grass on the edge of a field grows stonecrop. It’s a plant from the succulent family, with thick, juicy leaves. In one of his creations, Mathieu uses the plant raw, the leaves topping an arancini made with wild garlic and artichoke. He adds shoots from a rose bush growing in the castle gardens and some wild pea leaves.

The wild garlic arancini is topped with artichoke, stonecrop leaves and rose shoots. Photo: Romain Gamba 

You could also lightly fry the stonecrop leaves in some olive oil and use them as a side dish, for example to go with fish, Mathieu says.

The pandemic was tough for the chef, not only because of worries over what to do with staff and how to stay afloat. “It’s like being a musician without a stage,” he says. Speaking to Delano before the restaurant’s reopening on 19 May, the kitchen sat eerily quiet, the halls of the château empty, no tables set.

Nature provides

The restaurant is an experience. There is no “à la carte” option--Mathieu serves a variety of dishes he has created with local, seasonal produce and his foraged bounty. The menu changes with the seasons, with the weather, but is always vegetarian. In the château’s Côté Cour brasserie, diners have the option of adding meat, poultry or fish. “But it’s never the main event,” says Mathieu.

“Why vegetables? It’s easier to do yourself. You don’t just stick a cow in your garden,” the chef says. And it’s all about variety. “You shouldn’t eat the same vegetables all the time, either. Each season will provide what you need. The vegetables will grow with the seasons. We never use tomatoes in winter,” he says.

This year is marked by a one-month delay, according to Mathieu, with late frost, low temperatures and a lot of rain keeping nature dormant. As what becomes available changes, so does Mathieu’s menu.

A drink pairing option includes wine but also pressed juices or tisanes; it all depends on what works best with the food. Pressed ground-ivy, for example, adds a minty, fresh taste to chilled apple juice. It can also be used in patisserie or sorbets but shouldn’t be confused with common ivy, which is inedible.

The comfrey leaves are fried in tempura batter with a mushroom farce between two leaves. Photo: Romain Gamba 

It’s one of Mathieu’s ground rules for foraging: “Take only what you know. Never pick what you don’t know.” Wild garlic closely resembles lily of the valley, which can be fatal when ingested, especially for children. Comfrey leaves look almost exactly like the leaves of the poisonous foxglove, which can cause heart attacks, and the two are easily confused when the foxglove isn’t in bloom.

Mathieu fries comfrey in a tempura batter, with a mushroom farce between two leaves, giving it a salty taste and texture not unlike sole fish. “It’s the sea in the forest,” he says. Another plant, yarrow, when deep fried resembles fried sardines. It can also be added raw, for example to a stir-fry of spring vegetables, adding a sweet, flowery flavour.

“Nature is sharing. I have two to three places I go; you let things re-grow,” he says, adding that foragers should never raze a spot. “I only take what we need for one day or a couple of days.”

Accolades

His unconventional approach has earned Mathieu a Michelin star. La Distillerie was the first restaurant in Luxembourg to receive one of the newly founded Michelin green stars for sustainability. In 2020, it was named the best vegetables restaurant in the world by green dining guide We’re Smart, and Gault&Millau crowned Mathieu the best chef in Luxembourg.

The accolades come with extra publicity. La Distillerie featured in an Arte documentary about Luxembourg that aired in March (available online in French and German until the end of June) amid other media appearances in Greater Region countries and in addition to a collaboration with supermarket chain Cactus, which aims to promote local produce and seasonal cooking. “There are really great products in Luxembourg,” Mathieu says.

Some customers still complain, he says, but it’s usually people who didn’t read up on the restaurant and its philosophy ahead of making their reservation. He admits that the concept might not be to everyone’s liking but for him, it’s a mindset.

Back in the forest, when asked about diseases the plants may carry, he says: “But people have no problem eating something full of pesticides. For 45 years I’ve been eating wild plants and it's never made me sick. You have to be cautious, that’s all.” For the restaurant, the gathered plants are soaked in a mixture of vinegar and oregano oil--a natural disinfectant--for around eight minutes and then rinsed before use.

Chopped cucumber and strawberries with whipped cream, topped with a beech sprout and other foraged plants. Photo: Romain Gamba 

Dandelion buds can become capers when pickled in vinegar, beech sprouts can be eaten raw, bittercress, woodruff, hazel shoots, chickweed… the forest is a smorgasbord of flavours; it’s all about the mix that Mathieu serves up.

Chopped cucumber and strawberries mixed with cream that has been whipped with a splash of vinegar might sound like an odd combination and it could work as a starter or a dessert. But topped with a variety of foraged blossoms it’s a combination of aromas that just works.

The concept is catching on. Eleven Madison Park--a high-end, three Michelin star restaurant in Manhattan--announced it would be going vegan as it emerges from the pandemic lockdown. Noma in Copenhagen, once the world’s best restaurant, also went plant-based as part of the Noma 2.0 revamp.

And so, Mathieu elevates vegetarian and vegan cooking to something of an art form, an experiment in fine dining. Plates are carefully assembled, offering a treat for the eyes as well as the tongue. “For me, it’s not a job. It’s just happiness.”