A CUT ABOVE: The Kobe beef flatiron steak at KO Prime is a winner.

The upscale, earthy tone is set the moment you walk in the door: Spire’s blue and silver scrims have been tossed, replaced by iconic steakhouse reds and blacks, oversize wineglasses and flatware, and steak knives proportioned for professional football players. The carpet, too, draws you in with what looks to be cowhide, with the hair left on. It’s plush and keeps the noise down. Above, the ceiling is made of circular cutouts, which reveal portions of Grant Wood’s American Gothic: iconic heartland beef imagery, but with a postmodern presentation.

You’ll start glowing at the breadbasket, with its superb artisanal multi-grain, French, and sourdough rye. The appetizer of bone marrow ($11) is already a buzz item here. It brings three nice soup bones loaded with marrow, a garnish of “oxtail jam” (an intensely beefy flavor to cut the richness of the marrow), and grain mustard. Seared terrine of foie gras ($19) is more familiar, but the flavor, subtly enhanced by browning and an herbal undertone, is not. It’s garnished with a tower of sliced, stewed rhubarb and a square of what tastes like rhubarb paper. The fried-crab special ($16) benefited from soft-shell crab, and was complemented by heirloom tomatoes and salad.

Don’t allow the more unusual items to distract you from those that are tried and true; the market-green salad ($12) here is full of surprises: purslane, basil, tarragon, mitsuba, radishes, micro-green beans, a long wiggly shave of carrot, and lots of edible flowers.

Our first taste of Japanese-type beef, a Wagyu beef tartare ($19), was shredded with capers and pickles, with a raw-egg-yolk garnish in a nearly intact shell. Despite visual and textural appeal, the subtleties of Wagyu beef tend to vanish in this preparation. (Carpaccio may be a more effective fusion.) The lobster bisque ($14) was also a bit of a disappointment; it was creamy and rich but too subtly flavored by lobster, pepper, and tarragon. By the time the waiter poured it out of a pitcher into a shallow bowl with a little island of lobster meat and crème frâiche, it wasn’t very hot soup, either.

My nominee for KO’s signature steak would be the Kobe beef flatiron steak ($38/ 10 ounces). Even cooked medium-well, it had the beefy flavor of an aged sirloin and was tenderer than shoulder steak — an excellent use of a lesser cut of Japanese beef. I also liked the skirt steak with North African spices ($24/10 ounces) that came pre-sliced and unusually tender, with a peppery crust. (Most steaks were prepared a degree more than ordered, despite the waiter’s warnings of outrageous 45-minute cooking times for well-done steaks.)

I wasn’t knocked out by the American prime beef of the NY strip steak ($39), which was delicious, but not as flavorful as the dry-aged steaks featured by steakhouse chains. And the bone-in kurabuta pork shoulder ($32) was a bit off, since it seemed to have rib bones. The long-cooking process eliminated some of the advantages of the fattier and more flavorful heirloom pork; plus, it was overwhelmed by a salty, coffee-based glaze that was good but not complementary. On the plus side, it came with excellent pieces of white turnip.

The fish list at KO Prime runs to meaty-tasting fish such as striped bass, king salmon, and swordfish. We tried Dover sole ($48), an old favorite at the lamented Ritz-Carlton dining room. It was good, but not as meaty as usual, and thus overwhelmed by the usual capers-and-brown-butter sauce.

Following the steakhouse format, vegetables and starches were offered à la carte. Most are smallish and rich, though suitable for two people. Asparagus ($7) is peeled and served with delicious Hollandaise. Creamy spinach ($6) adds a dollop of melted mascarpone to upgrade the steakhouse standard. And Aligot potatoes ($8) are whipped with cheese and incredibly rich. Three kinds of wild mushrooms are also available, but the mixed mushrooms plate ($8) doesn’t skimp on the usual morels or hen of the woods.