On my nightstand sits a stack of food-related books, one of which is Service Included, a tell-all by former Per Se server Phoebe Damrosch. My favorite chapter so far is "No Bones About It," in which Damrosch details her glutinous search for New York City's best bone marrow. For those who haven't tried it, dining on bone marrow may sound weird, even gross. But one bite of the rich, beefy "jam," and you'll be hooked. Thanks to a trend that's sweeping the nation, roasted shank bones are showing up on more menus. The Fort, which has been serving bison bones with sourdough crostini and port-bison reduction for decades, now finds competition from Denver restaurants such as Bones, where the app is paired with grilled bread and fig jam. So, what's driving the trend? The economy, for one, since the menu addition is a well-priced indulgence. Secondly, putting bones on the menu goes hand-in-hand with another trend, nose-to-tail dining, which encourages restaurants to makes use of the whole animal. Bonus: For anyone who has ordered osso buco, you've already experienced bone marrow's appeal. In this traditional Italian dish (which translates to "pierced bone") the sauce is partly flavored by marrow--and the meal is often served with a small spoon with which to scoop out the bones. Check out a classic rendition at Locanda del Borgo on osso buco night (Thursday, April 2).