This is an amazing martini. I go light on the elderflower and heavy on the Plymouth. The English Martini is the reason I remember to water my rosemary.
I made this drink with Aviation gin, because my wife isn't a huge fan of juniper but I wanted to use some of the rosemary we had. It's a very enjoyable drink, with all three elements being present. I did adjust the recipe to make it smaller, but it looks very nice in a Nick and Nora glass.
This drink is one of my absolute favorites-- a go to. However, I prefer different proportions. I mix a 5:1 ratio, usually 2.5 oz. gin, .5 oz elderflower. Basically, I'm treating the liqueur as a vermouth stand-in. I also generally Stir rather than Shake. The gin really carries this, with the herbal and floral notes giving it a bright pop and roundness. Not too sweet.