Welcome to The Supersonic, Blackbird’s newsletter for the restaurant-obsessed. If this is your first time with us, please enjoy a subscription on the house. James Beard, the pioneering chef, invented the modern restaurant burger, or so argues Beard-winner John Birdsall, author of “The Man Who Ate Too Much: The Biography of James Beard.” According to Birdsall, Beard offered steakburgers in the early '50s, an era when only hamburger stands served the fast-food staple.