Quite good! This will be sensitive to the specific mezcal used. I used Mal Bien 100% Espadin and it worked well. This is an artesanal but fairly tame mezcal. For everyday use I usually use Bulleit "95" rye but for this I used A.Overholt "Monongahela Mash" straight rye (95 proof, 80% rye, 20% barley malt, non-chill-filtered).
Tried it with lime juice, a light reposado tequila, and did not dump any of the Pernod. For me, much better.
The wife and I, along with our Japanese friends, fell in love with this cocktail when we discovered Iwai "45" whisky from the Mars distillery. 80% corn, 20% malted barley, often compared to bourbon but I say that is ridiculous: if it can be compared to anything it would have to be a Canadian. The reason it works is its refined elegance, which allows it to harmonize with the other ingredients. This drink is a classy lady of great charm.
The impression this makes will vary enormously depending on the tequila used. With tequila Ocho it was sublime, with Sauza "Hornitos" it was good but not exciting. I recommend Dolin Blanc, as I don't think tequila stands up to the funkier Italian biancos. It's the same story with gin martinis.
Tried it both ways - green and red shiso. In either case, the shiso is subtle. As expected, the red has a bit more "tang" and the green more herbal. Both very good. I had to make my own vanilla syrup using 2:1 sugar syrup and Madagascar vanilla extract. My syrup is too sweet, but if the sweetness is restrained this is a very nice brandy sour.
The photo causes me to ask if the shiso leaf used in the shaker should be the green or red variety.
Really nice summer drink. To make use of ingredients on hand, and to boost the ginger component, I used 2 oz Bulleit "95" rye, dropped the syrup, and added 1 oz Barrow's Intense Ginger. This was really good even without any ginger ale. Add ginger ale to make it sweeter and easier to chug down in a one-er.