IT'S AN ART Hold the tomato: the Frenchie burger at DBGB includes a compote instead.

TECHNIQUE MATTERS. SO DOES THE BUN Michael David, right, created the Comme Ca burger. The bun is by Hidefumi Kubota.

THE simple hamburger isn’t so simple any more.

Over the last decade or so, there has hardly been a serious chef in America who hasn’t taken a shot at reinventing or improving it. They have trained their skills on every element, from the precise grind of beef to the ketchup and pickles. Some have turned their bakers loose on reformulating the bun.

By most accounts, the burger’s upward journey began eight years ago, when Daniel Boulud stuffed ground sirloin with truffles, braised short ribs and foie gras at his DB Bistro Moderne in Manhattan. A few weeks ago, Mr. Boulud brought things full circle, opening a burger bar on the Bowery called DBGB Kitchen and Bar.