Virtue Feed & Grain’s roasted marrow bones are topped with a zippy gremolata.

In a culinary beauty contest, bone marrow wins no tiaras. Cooked expertly, it arrives on your plate as a gray, viscous, jellylike substance, usually encased in the vessel from whence it came — the whitish, ghostlike leg bone of a cow.

But like the oyster (another gastronomical ugly duckling), marrow is revered by foodies as one of the great culinary pleasures. Enthusiasts describe it in the same rapturous tones they use for a fine foie gras.

Even chefs have a hard time explaining the appeal of this unlikely delicacy, which is usually served as an appetizer. “It’s this luxurious thing that you can’t quite put your finger on,” says Ryan Wheeler, the chef at Old Town’s Virtue Feed and Grain. “All you know is that you know you want more.”

One reason might be the fat content that gives marrow all the richness of a beef-flavored butter; marrow itself is mostly made up of fatty cells. When bones arrive from the butcher — typically in segments of a few inches — the core of marrow is pinkish and opaque. When roasted, it softens and becomes more translucent, ready to be scooped out with a spoon or knife (some restaurants serve it with a slender implement for scraping the prized goo out of the narrow bone shaft).

Chefs almost always plate it with a bit of bread, onto which diners can smear the marrow as if it’s jam. Most counter its heft with bright flavors.

The herb-topped marrow bones at Brixton are served with a savory-sweet onion jam.

Wheeler, for example, dabs a dollop of gremolata — a zippy paste of shallot, garlic, parsley and chili flakes shot through with lemon zest — on his bones ($6) before roasting them. The flavors melt into the hot marrow to form a surprisingly light spread for bread. And at Petworth bistro Chez Billy, the marrow bones ($10) get a vinegary bite from a pickled shallot accompaniment; it’s a Paris vs. Deep South mashup.

At Blue Duck Tavern, the bones ($14) are topped with an elegant crust that provides a textural counterpoint to the soft marrow. Bones are split lengthwise (a touch that makes the scooping process a little more dignified) and topped with bread crumbs leavened with a snappy mixture of black, pink and green ground peppercorns, and a dusting of smoky espelette (pepper from the Basque region of France).

Brixton, the new British-accented pub on U Street, takes a different approach to the dish ($12). Instead of employing contrasting flavors and textures, the chef doubles down on a single taste profile, serving the bones simply seasoned and paired with a savory-sweet onion jam that mimics the texture of the marrow itself.

Blue Duck sous chef Matt Demery says the marrow bones are one of the few dishes with a permanent spot on the menu. “Popular demand,” he explains.

But not everyone’s so blase about bones. Wheeler sees many diners wary of the dish. “It’s like sweetbreads,” he says. “People aren’t sure what they are, and they aren’t sure they’ll like it. So I have to do a little education sometimes.”

He says it’s his enthusiasm for the dish — “it’s so unctuous, so delicious,” he raves — that usually convinces skeptics.

Cult Status

Although European kings and peasants alike feasted on bone marrow, its contemporary cult status has much to do with British chef Fergus Henderson. He helped spawn the current mania for “nose-to-tail” cuisine — the gastropub trend of using all parts of an animal, even the nastier scraps that most American chefs usually discard. Henderson’s roasted marrow bones with parsley salad — a dish from his London restaurant, St. John, which opened in 1994 — is considered a modern classic.

Virtue Feed and Grain, 106 S. Union St., Alexandria; 571-970-3669.
Chez Billy, 3815 Georgia Ave. NW; 202-506-2080.
Blue Duck Tavern, 1201 24th St. NW; 202-419-6755.
Brixton, 901 U St. NW; 202-560-5045.