Shiso Cocktail Revisited

An improved version of the shiso celery cocktail:

1.75 oz Old Tom Gin (used Hayden's in this round)
0.75 oz St. Germain
0.5 oz Lime Juice
3 shakes Celery Bitters
2 leaves green shiso
1 inch Japanese cucumber

muddle shiso and cucumber
add st. germain, muddle more
add in lime juice, gin, celery bitters
shake