Grilled Turbot with “Holy Water”

First of all, forget about getting the original recipe for “holy water, ” the sherry glaze that goes on Elkano’s renowned grilled turbot. “Only three people know how to make it, ” says Luis Mari Manterola, the restaurant’s grill master for more than three decades. “We prepare it at night when the restaurant is closed.” Elkano is the granddaddy of grilled seafood restaurants in the Basque fishing town of Getaria outside of San Sebastián. Turbot is the house specialty, grille