A greasy spoon among silver spoons, the Burger Joint is hidden behind a curtain in the lobby of the ultra-swank Thompson Central Park New York Hotel. Pull back that curtain and you enter a hidden diner that looks like it was yanked off some side street in Detroit. But it serves up the juiciest, most perfectly charred burgers in the western half of Midtown. Order them with “the works” (red onions, lettuce, tomato, pickles, mustard, and mayo) for not a cent extra.