There is no single "official" standalone PDF sold directly by the publisher for the full encyclopedia. However, you can find digital access through several legitimate channels:
Finding a free PDF of the 2006 or 2015 editions is technically piracy. larousse gastronomique espa%C3%B1ol pdf
Amazon offers the Larousse Gastronomique Español for Kindle. There is no single "official" standalone PDF sold