Add the mint leaves (preserving the top of the sprig) to the small half of a cocktail tin.
Add the matcha honey syrup and gently press the mint into the syrup with a cocktail muddler, or another blunt object.
Add the fresh lemon juice and whiskey.
Add 5 ice cubes to the tin, seal with the other side and shake hard for 8-10 seconds.
Double strain (using a Hawthorne and fine mesh strainer) into a rocks glass over fresh ice.
Garnish with the top of a mint sprig. For added aromatics, gently tap the mint to the back of your hand before tucking it into the glass.