The way that I created this was with kümmel. I also noted that the recipe written that way was best with a lighter style kümmel (a liqueur unlike aquavit which is a spirit) like Helbing. When I made it at work at River Bar in Somerville, MA, with the more potent Combier Kümmel, I needed to cut this to 1/4 oz (you can replace the rest with a 1/4 oz simple if desired or leave it out to be less sweet).

Fred - Got it. The OP had adapted your drink and I reverted it to your specs. I even got the kummel right in the note but not in the drink, so it's fixed now. Thanks, Zachary

The reference shows/states to shake with crushed ice and then pour unstrained.

Overwhelmingly mezcal

Knob Creek often overwhelms cocktails, but here it's perfect.

Quite good. I used Del Maguey Vida for the Mezcal. There is a lot of complex flavor here beyond the more noticeable earthy mezcal that is more noticeable. The Punt e Mes provides some welcome bitterness to the finish. The ratios seem right.

From what I can tell, the original recipe called for Beefeater in 2002, but not Beefeater 24 (which has teas as part of its profile) since the latter was not released until October 2008. [There is a typo in one article that says something about it being in 45 markets in 2004, but it doesn't match the rest of the article and was likely meant to be 2014 based on the article's 2015 date.] Dr. Adam Elmegirab's Book of Bitters lists the venue as Mad Fox in Amsterdam. Difford's says 2002 at Milk & Honey, London. I am wondering if the competition it was created for was in Amsterdam, since all appearances are that Chris Jepson was working in London at the time. At any rate, its long time inclusion on Milk & Honey's menu is what drove its popularity.

Curated to correct gin, a note added about Beefeater 24 error, and a link added to reference an article published yesterday (which I didn't see until today, eerie coincidence) about the history of this cocktail.

It is a lovely drink. I particularly enjoyed a slight variation published by Adam Elmegirab which uses 3 dashes of his Spanish Bitters in place of the two dashes of orange bitters. The Spanish bitters are a more floral/fruity, semi-orange bitters which fit seamlessly into this recipe.

Lillet is completely overpowered, tastes like a triple sec martini.

Too boozy for me even though I enjoy an occasional martini

We don't normally publish simple Negroni variations because the database would quickly become littered with nearly-identical, similar-sounding cocktails. We allowed this primarily because of the reference and the generally-good cocktails from the source restaurant.