Here is the boring (but important) part. Larousse is an active publishing house. While you can find scanned copies of the original 1938 French edition floating around in the public domain, the modern "Español" edition is copyrighted.
Finding a free PDF of the 2006 or 2015 editions is technically piracy. larousse gastronomique espa%C3%B1ol pdf
However, there is good news for the digital purist: Here is the boring (but important) part
Before you click on that shady link promising a free PDF, consider these risks: larousse gastronomique espa%C3%B1ol pdf
Sometimes you buy the ePub (Kindle/Google) but want a PDF for printing a few pages. Here is a legal method for personal use only: