Just a few years ago, bone marrow was one of those items Pittsburgh chefs said they loved, but couldn't sell. But trends change quickly and so has the Pittsburgh restaurant scene.

Now, bone marrow is on menus all over town, and it's flying out of kitchens faster than most of us ever expected.

Preparations range from traditional to unexpected: At Salt of the Earth, chef Kevin Sousa uses bone marrow to bind beef tartar. Restaurant Echo in Cranberry serves traditionally roasted, cross-cut bones with a parsley salad and also uses marrow to enrich their bordelaise sauce.

This past winter, marrow bones were on the menu at Toast! Kitchen and Wine Bar in Shadyside, accompanied by a surprising black bean puree. Sam DiBattista, chef-owner of Vivo Kitchen in Sewickley, serves cross-cut, baked marrow bones with a distinctly untraditional tamarind sauce.

"It has a tartness and a sweetness to it that I really like," he said.

To the uninitiated, bone marrow can seem foreign, even a little disgusting. But the soft, fatty tissue found in the hollow center of animal leg bones has been eaten and enjoyed for millions of years.

When raw, the marrow looks almost like part of the bone. It's off-white and hard with a slightly spongy texture. Once it's cooked, it becomes soft and rich, melts easily and tastes almost like butter, with a sweet, nutty flavor and a lighter, more delicate texture.

Jennifer McLagan, a noted cookbook author, likes bone marrow so much, she's featured it in three cookbooks, most recently, "Odd Bits: How to Cook the Rest of the Animal" (Ten Speed Press, 2011, $35). She's noticed a general growth in the ingredient's popularity.

"It's been around for a while, but bone marrow seems to be going mainstream," she said.

And why not? Marrow is cheap, nourishing and tastes fantastic.

"Bone marrow is a bit like the poor man's foie gras. It has that wonderful smooth texture and fabulous taste and it's generally not that expensive," Ms. McLagan explained.

And while it's rich, it's arguably quite healthful, because it contains a lot of monounsaturated fats. In her cookbook, "Fat: An Appreciation of a Misunderstood Ingredient, With Recipes," she argues that fat is an essential, healthy ingredient and that many animal fats, like bone marrow, are wrongly maligned as unhealthful and artery clogging, when in fact they have a lot in common with olive oil. According to her book, the fat in calf bone marrow is typically 31 percent saturated, 63 percent monounsaturated and 6 percent polyunsaturated.

Healthy or not, most people who eat bone marrow do so for the wonderful taste and texture, not to mention the visceral pleasure of eating out of the bone. "It appeals to something really basic in our genetic code," Ms. McLagan said.

Many of the most popular bone marrow dishes involve eating straight from the bone, often with a small, specialized spoon. Osso buco, the well-known Italian specialty of braised veal shanks, is loosely translated as "bone with a hole," referring to the fact that the veal shanks are cross-cut, allowing the eater to enjoy the marrow, as well as the tender, braised meat.

This dish is less common than it once was but still has quite a passionate following. Girasole in Shadyside offers it on the last full weekend of each month. It's also frequently on the menu at Brix Wood-Fired Wine Bar, which recently opened on the North Side.

As more restaurants serve bone marrow, chefs are coming up with new twists to distinguish themselves. Chef Keith Fuller had served cross-cut, roasted bones in his previous position at Six Penn Kitchen, Downtown. At his new restaurant, Root 174 in Regent Square, he had wanted to serve them cut lengthwise, or canoe-style, topped with an apple gremolata and parmesan cheese and served with toasts. But then he heard about the gargantuan servings of canoe-cut bone marrow that chef Richard DeShantz was serving at Meat & Potatoes in the Cultural District. He decided to find a different way to prepare them.

"My sous chef was making creme brulee," said Mr. Fuller, and he then thought, "What if we make an unsweetened creme brulee, whip in the bone marrow and brulee it with parmesan?" After a little trial and error, the bone marrow creme brulee was born. At first he offered it as a special, but the response was so enthusiastic, it was added to the regular menu.

The bone marrow creme brulee -- refined, whimsical and delicious -- is a striking example of what happens when trends drive creativity rather than imitation. And when chefs are comfortable taking risks and offering something different, diners have more reasons than ever to take a seat and enjoy.

First Published: September 29, 2011, 8:00 a.m.