These recipes must have been on my system for ever, but I didn't find them until 30 March 2024. They come from the USENET alt.gourmand group, and they date from 1985 to 1989, before the World-wide web and mainly even before I had my first Unix machine. They're all in troff markup. The ones I checked require the mm or ms macro sets. There are 565 of them.

=== grog@hydra (/dev/pts/28) ~/public_html/recipes/alt.gourmand/recipes 57 -> ls | wc -l
     565

From the file Introduction, it appears to be a snapshot of the USENET cookbook. I've converted it to printable ASCII at Introduction.txt. Admire the “Printed 30 March 19124”, one of the last vestiges of Y2K. I've taken a look at a couple, but they don't look very interesting.