The right kind of clashing is far more interesting than the most scrupulous matchy-matching. Brand-new Restaurant Marron, installed in the former Olivar space in the Loveless Building off the north end of Broadway, doesn't match its historic home, and it also doesn't match your idea of an expensive prix-fixe restaurant. The room's locally famous deco murals depict a Pushkin fairy-tale scene, with big chalices and berobed travelers and whole birds on platters held aloft. There's no mead or joints of meat at Restaurant Marron, though; chef/owner Eric Sakai makes highly composed, haute New American food, starting with an entrĂ©e plus dessert for $39, with a five-course "petit voyage" at $78 and the carte blanche of eight courses (which the whole table must order) priced as quoted. Wine pairings are $45 or $72. Nor has the low-ceilinged, medieval-rustic-feeling room been outfitted with the usual trappings or tenor of a reverent temple to foodism. Tablecloths are absent, cutlery and plates are mismatched, and dressed-down, chipper servers might announce, "Sun gold tomatoes, the first of the season—yay! Summer's here!" Stainless-steel wire kitchen shelves—out in the open, with the murals showing through—hold sundries and piles of cookbooks. The soundtrack might be vintage French pop music, Nancy Sinatra, or beboppy jazz.

The Marron website promises all-lower-case "inventive cuisine; casual, come-as-you-are setting," and the answer to a dress-code question is just "nope." But the techniques are classical, and the word "marron" is French (for chestnut). The man who dined alone here, studiously photographing each course, seemed sort of like he was in the right place, but also sort of not.

The haute element at Marron is legitimate: Eric Sakai has worked at fancy Rubicon and Acquerello in San Francisco and, more recently, the schmancy Four Seasons Jackson Hole. Partner and beverage-master Zarina Sakai comes from even the even hauter Jean-Georges and the French Laundry.

Zarina's enthusiasm is disarming—she's the one who said "yay!"—and she makes her lengthy wine list interesting and welcoming. My friend and I ordered some sparkling CrĂ©mant rosĂ©, which met with her approval—just right for summertime, and "doughy," she said—and one "petit voyage" plus one entrĂ©e and dessert. We shared everything, which proved to be filling but not overly so, enjoyably protracted but not overlong, and plenty of fun. Zarina was our server most of the time, with two more friendly types filling in; the petit voyage, she explained, would include selections from the menu plus a few treats. Her already bountiful good cheer increased when we said we'd like the chef to choose our additional entrĂ©e; she was genuinely, transparently surprised and pleased.

The amuse-bouche, a shot of cool, celadon-colored cucumber and Thai basil soup topped with a white fluff of goat whey foam, was impressive to hear about, lovely to look at, and bland. There was nothing wrong with it, but the first course that followed was another chilled soup, and it was spectacular. Made with the aforementioned exciting sun gold tomatoes, which had been smoked, plus confit cherry tomato, green strawberries, Espelette pepper, and fresh basil, it was sweet and piquant at once, both rich and refreshing, and brightened with what another server confirmed was "a touch of white wine vinegar." Yay, indeed!

Next up, a warm salad of skinny, crisp green and gold beans with turnips, mint, and breadcrumbs had a soft-cooked egg on top and a dressing made with "spicy 'nduja," which a non-Zarina server haltingly and minimalistically described as "pork... sausage." 'Nduja is an Italian salami from Calabria, cured in a casing but soft and spreadable. The possibility of spicy and porky dressing, soft and rich egg, and crunchy and colorful vegetables commingling was intriguing, but it was hard to get all the elements in one bite; it was a fine salad, but it just wasn't as completely realized as some of Eric's work. Like, for example, the next course, a perfectly cooked piece of almost-sweet-fleshed sea bream, the skin side salted and spiced and seared for ideal contrast. It came with bits of collard green, sweet Nantes carrots, and a cumin-carrot vinaigrette, and it was fantastic.

And the entrées were excellent: an exquisitely tender grass-fed lamb striploin, and one of the best pieces of duck breast I've ever had the pleasure of meeting. Both were cooked unerringly medium rare, and both had caramelized fatty edges that helped the meat melt in the mouth. The duck entrée had the bonus of a roulade of super-savory confit, while the lamb had cherries; otherwise, oddly, both were served with the exact same accompaniments of miniature chanterelles, summer squash, and a "bagna càuda" jus (Marron's quotation marks; the usual formulation includes garlic and anchovies, but this one was not at all fishy, tasting like an especially deeply flavored pan sauce). The lamb's addition of cherries actually seemed like it would have done even more magic with the duck.

Our palate cleanser was a third cold soup—arguably cold-soup overkill, but it made sense after the dark, meaty richness of lamb and duck. It was pureed peach and vermouth, and it was the fluffy, sweet right step toward two desserts: an impressive vertical stack of the world's most delicate, Meyer lemon–scented sponge cake with peaches and toasted cashew ice milk, and single-origin dark chocolate mousse with cherries transformed into a cloudlike texture, plus crùme fraüche and a sprinkle of sunflower seeds. Both were unusual, thoughtful, and very, very good.

Before opening Restaurant Marron, Eric told the blog Capitol Hill Seattle that he wanted "a clean space that is void of distractions—off white and charcoal," and that he was working with his contractor to cover the murals, keeping them intact but hiding them away. The resulting minor landslide of comments in opposition there and on Eater Seattle appears to have convinced him otherwise, which is good. But the cold, bluish track lighting shining on the warm, old walls needs to be adjusted. There's no reason that the new and the old can't peacefully coexist here, just like the haute and the "yay!" recommended