Rost Boeuf
Slang for happy drugs like ecstasy or mdma that are tremendously good fun, when used in the correct environs, such as a large German techno rave dungeon, or oubliette.
"Would you care for some rost boeuf, monsieur? I put it to you, sir, that you are not raving hard enough, at least, not to the standard to which I, after three morsels of this extraordinary narcotic, have become accustomed to."