Dearfolk,
If all else fails, try blending about 80% Gulden’s Brown Mustard with 20% Tulkoff Horseradish and throwing in a bit of red pepper. You can reproportion to your own taste by using small amounts to begin with until you get it right for you.
I wouldn’t try horseradish with yellow mustard myself, but it might work.
I’ll come back here to see what transpires.
Hotter And Hotter, Ort. Carlton in Colder And Colder Athens, Georgia.

Wow, McSorleys… Been about a dozen years since I was there (And in NY for that matter).. What a pleasurable memory! Try this site: http://www.topsecretrecipes.com . Not sure if they have it, but maybe place a post there to find it.. Good Luck…

Ted, While you wait for that recipe, consider trying a jar of the imported Polish mustard I use all the time (delicious, spicy and medium hot). It’s name: Pulaski Stone Ground Polish Style Mustard. Made with natural ingredients, it’s inexpensive and is sold in the ethnic food sections of large supermarkets.

Of course, in NYC, you can get any number of excellent spicy hot mustards. I wish you well on the McSorley’s search.