Restaurants that combine themselves with novelties can veer in any number of directions. It can be charming, as in Fritz’s Railroad Restaurant, a 63-year-old chain in Kansas City where you order via a phone at your table and your food arrives on a train track above your head. Or it can be a dystopian hellscape, like Chuck E. Cheese.
The concept behind Onsen, a Japanese spa-restaurant in the former City Automotive building in the Tenderloin, is anything but gimmicky. Maybe your first mental image is of shrimp tempura in the steam room, but from top to bottom (and from dry sauna to cold plunge) this model is a paragon of elegance. The light emanating from Himalayan-salt-block window in that dry sauna is gorgeous enough, but the fact that Onsen puts out food this outstanding from a kitchen that tiny is even more impressive.
In addition to being the one-man electro-psych band from L.A., onsen is the Japanese term for a resort centered on a hot spring, and the bath is the primary half. Wife-and-husband team Caroline Smith and Sunny Simmons spent a few years living in the building, inside an Airstream, as they built the space out. At $30 for the first hour-and-45-minutes and $10 per hour after that, the bath they created together isn’t expensive, either.
Shuttle among the warm pool, the dry sauna, the steam room — which is mildly claustrophobic when you experience the steam come on for the first time — and the bracing cold shower, a pull-chain installation in corner that blasts you with frigid water from several spouts. (Note: Most days are open to all, with bathing suits required, but on Onsen’s single-gender days, you may bare all. Plan accordingly.) You can get a massage, too. The mood is chill, neither rigidly silent nor full of inane yammering. Cyborg that I’ve become, spending several hours without access to my phone or any reading material felt like it might lead to arrhythmic spasms or possibly involuntary lycanthropy, but I blissed out right away. Drinking cup after cup of water and tea, I watched the light gradually change as the afternoon wore on. Hit that pool enough times after sweating out the toxins and you may even stop worrying about the neo-Nazi takeover for a bit.
Then it was chow time. I thought I achieved a level of relaxation on par with total metabolic shutdown, but bath-time sharpened my appetite into a katana-like blade. It’s not altogether unreasonable for a table for two to order Onsen’s entire menu of bites, skewers, and plates, which we did on every visit. Don’t skip any of the bites, from the fennel and Chinese plum-heavy pickles ($6) to the stunning rice porridge with a pickled quail egg ($7), with a bit of uni detectable at the back of the palate. A sensuous soft-egg custard ($9) was equally fantastic, tasting of bacon even though it contained “only” crab and shiitake mushrooms.
Ranging from the serviceable pumpkin ($6/$11) with a solid shiso verde to the superior Monterey squid with sancho pepper and kaffir lime ($7/$13), the skewers — each available in large and small portions — are, by default, the least exotic segment of the menu. But a lot of effort has been put in to sex them up visually. Skewered in an S-shape, the uni-rich sardines come whole, with the blank eyes of ancient Greek statuary, while the squid look like the monster in Stranger Things when it’s mad. Lamb will always and forever be my favorite meat, but the texture of these little bites ($8/$15) was bordering on ridiculous: a little melty, a little resilient against the tongue. I’ve never eaten anything remotely like that.
Among the bigger plates, I found the horseradish on the smoked trout to be a little muted, although my dining companion strenuously objected to this, saying that it balanced the spaghettied rutabaga and the yuzu cream. The only real disappointment on any visit was the bowl of generic udon noodles ($16), which were overcooked, too full of soy sauce, and resting under a jidori egg that was almost hard-boiled. (If you can’t swirl the yolk around, what’s the point?) Other than that, everything was truly excellent. Charred brassicas ($13) might have been the weirdest dish, with strips of green-black kelp atop a cauliflower puree that looked like popcorn in sauce veloute. They’re delicious, with yet another wonderful texture. A preparation of beans and carrots ($13) hid coyly under a bit too much radicchio, but the shiso verde was a better addition here than on the pumpkin skewers. If, like the skewers, the mushroom dumplings in katsuboushi broth ($15) forego creativity for technical excellence instead, they achieved a high level of earthiness with a fair amount of dill. For dessert, I pretty much always find green tea ice cream to be a bore, and if Onsen’s soft-serve didn’t exactly convert me outright, it’s still among the best out there, served with a sake Kit-Kat.
There are but two beers and two wines, but for being nine strong, the sake selection is about as wide in scope as any I’ve ever had. (Disclosure: I have never visited Japan.) In isolation, I adored the floral, saline Cabin in the Snow ($11) but the nuttier, unfiltered Dreamy Clouds had a longer finish and held up better against the food’s stronger flavors. If you get the $15 flight of three, throw in the gin-like Honkara, which makes a great aperitif.
At about the two-thirds mark on every visit, I felt the same sentiment: giddiness. Onsen makes me giddy, because it’s beautiful and well-executed — but most of all, because it’s unique. You sweat out the toxins, fill your body with nourishment (and sake), and on your way to the restroom, you have a laugh at the shelf of Nekozushi sushi-cat keychains. (“Why am I sushi?” asks the kitty on the side of the box.) Why, indeed? On a related note, why do auto body shops always seem to have such good bones, the better to transform them into stunning Japanese spa-restaurants a century after they’re built? There may not be any motorcycle maintenance in here anymore, but there’s plenty of zen.
Peter Lawrence Kane is SF Weekly’s arts & culture editor.
Onsen Bath & Restaurant, 466 Eddy St., 415-441-4987 or onsensf.com