In which classical opera was "chocolate" made reference to,by the author?

The Chocolate Soldier (Der Tapfere Soldat ), with music by Oscar Straus (The Waltz Dream ) and lyrics by Rudolph Bernauer and Leopold Jacobson, was based on George Bernard Shaw's 1903 play, Arms and the Man

Not to diminish the work of B.Shaw, I was looking more into the "Serious sacred kind of opera" from the 16th Century.

I'd like to make a correction about my last post.I meant the 18th Century (the 1700's).OOps sorry.

Mozart made reference to chocolate in his opera, Cosi fan tutte.

Premiered in Vienna, January 26, 1790

I did indeed Paul, Thank you! Many sites can be found in reference to this,here is one of them.