Very nice as a nightcap. Not too boozy and on the sweet side.
Maybe something for a friend who is not into cocktails

Surprisingly soft cocktail. Not flavourless but elegant. Really like the way each ingredient stands on its own.

Lacking Irish whiskey and inspired by comments, I improvised with the following:
45ml Monkey Shoulder
15ml Carpano Antica
7.5ml Green Chartreuse
2 dashes of orange bitters
The result? A nicely balanced cocktail where each ingredient's flavor stood out.

2 dashes Angostura bitters tames the Chartreuse, I think.
Mine otherwise had Bushmills, Carpano Antico, and Green Chartreuse.

I don't want to imagine how the original equal parts version must taste, even with only 10ml, chartreuse dominates a bit too much for me...

I didn't like it at first, but it's growing on me.

I liked the sound of this, but didn't have Irish whiskey so I subbed in Japanese blended whiskey. It was a solid 3.5/5, and for round 2, I used the original equal parts recipe and it was even better, 4.5/5. Definitely one I'll try again.

You have to play with the amounts to your taste but these three ingredients make one of my favorite cocktails.