Umami Burger Comes to New York, Armed With One Addictive Ingredient

When he's asked, as he often is these days, about the much-anticipated smackdown between Danny Meyer's East Coast Shake Shack franchise and his West Coast Umami Burger, which is coming this summer to a New York neighborhood near you, Adam Fleischman likes to make a few things clear. First off, he wants New Yorkers to know that his L.A. Umami ­Burger empire--which has grown, in just four short years, from a $40,000 ­investment to a multimillion-dollar enterprise with madly popular, ever-multipl...