All cooking is elemental — a complex chemistry of heat, time and ingredients. But nothing beats the special alchemy that derives from preparing a meal over an open wood fire.

The hiss and crackle of the timber, the wafting aromas, the glow of the flames, the heat emanating from the embers: These are the primal qualities of wood-fired cooking that have fueled its growing popularity in fine dining restaurants around the world, including Japan.

That said, wood has rarely if ever played a role as a heat source in Japanese cuisine, given the availability of premium binchō charcoal that burns at such a consistent high heat. But one young chef who is starting to blur those lines is Yu Kunisue, whose remarkable new restaurant, Shizen, opened in January in Shibuya.

Kunisue’s background is in kaiseki, Japan’s traditional high-end cuisine. Still just 27, he trained for four years at Kaiseki Komuro in Tokyo’s Kagurazaka neighborhood, where he learned the fundamental cooking skills and seasonal recipes. By chance, he then took a short-term assignment to work at Japan’s consulate in Strasbourg, France. That is where he first came across the widespread practice of cooking over wood.

Chef Yu Kunisue’s hallmark at Shizen is cooking on an open wood fire. | ROBBIE SWINNERTON
Chef Yu Kunisue’s hallmark at Shizen is cooking on an open wood fire. | ROBBIE SWINNERTON

Determined to incorporate this into his own cuisine, after returning to Japan Kunisue joined the kitchen at Chofu Maruta, a restaurant in western Tokyo that has pioneered European-style wood-fired cooking in Japan. He later moved on to work with chef Hideaki Sakai at his much-lauded contemporary izakaya tavern Sakai Shokai and its sister operation, Sowado.

This connection led to Shizen becoming the third restaurant in Sakai’s group and Kunisue taking over the floor above Sakai Shokai (in the same nondescript building in a quiet backstreet of Shibuya). A steep climb up two flights of stairs — be warned, there is no elevator — brings you to Shizen’s heavy, battleship-gray metal door.

From the outside, it looks forbidding. Inside, though, the long, thin dining room is warm and inviting with roughly plastered walls in rustic shades of brown and a spacious, seven-seat counter that wraps around two sides of a narrow open kitchen.

At the far end of the room, built into the exterior wall is the fire pit. By the time you arrive, Kunisue will have lit the kindling and brought it up to heat. For much of the ensuing two hours or more, he will hover there, preparing the dishes for his multicourse omakase (chef’s choice) meals. Meanwhile, sous chef Motoki Kondo works in the center of the room at the cooking "island," which bears more than a passing resemblance to the traditional kamado stoves still widely used in old-school Kyoto restaurants.

Once the guests have arrived, each course is served to everyone simultaneously in the kaiseki style, with Kunisue calling out in Japanese a brief description of the ingredients and their provenance.

In all, dinner will comprise nine courses, while the weekend lunch is slightly abbreviated, featuring one fewer dish. There is no separate drinks menu. Each course comes with its dedicated pairing — either alcoholic (wine, sake and beer are all served) or nonalcoholic (mostly tea and mocktails) — included in the overall cost.

The final main dish at Shizen is rice slowly cooked over the wood fire, served with an array of his pickles and ferments. | ROBBIE SWINNERTON
The final main dish at Shizen is rice slowly cooked over the wood fire, served with an array of his pickles and ferments. | ROBBIE SWINNERTON

The most colorful dish is likely to be the hassun platter, a selection of half a dozen different seasonal specialties served on the same plate. These may include a deep-fried fritter of crunchy herring roe, some wakasagi smelt or a slice of juicy duck breast wrapped around vivid early spring flowering mustard greens.

The other standout feature of Shizen is Kunisue’s extensive use of fermented foods as accents or condiments in just about every dish. This, he says, was an interest picked up while he was at Maruta and one that became his major focus during the pandemic years.

Almost each course is likely to be served with its own ferments. Amadai (tilefish) is prepared by simply ladling hot oil over the scales to crisp them up. Kunisue pairs this with garnishes of fermented udo (spikenard) and fermented red camellia flowers, reflecting the blossoms of late winter.

Ditto with the sashimi plate. Kunisue lightly sears the skin of sumagatsuo (mackerel tuna) over a fiercely burning length of vine wood. He then slices and serves it not with a standard ponzu but a dipping sauce made from green tea and tomato fermented until it has developed its own natural acidity.

As always with kaiseki, the culmination of the meal is the rice course. Slowly cooked in a pot over the fire pit for half an hour or more, the white, fluffy grain is accompanied with a rich, warming miso soup and a selection of half a dozen homemade pickles. Colorful and bursting with life force, this is Kunisue’s way of underscoring that the name Shizen, from the Japanese word for "nature," is reflected in every aspect of his cooking.

Ogitsu Bldg. 3F, Shibuya 3-6-18, Shibuya Ward, Tokyo 150-0002; 080-6205-3918; sakai-shokai.jp/shizen/; open Mon-Fri from 7 p.m.; Sat., Sun., hols. at 12 & 6 p.m.; dinner ¥30,800 (including drinks pairing and tax), lunch ¥22,000; nearest station Shibuya; no smoking; major cards; some English spoken