Soak fresh-cut pineapple and fresh-cut ginger in Irish whiskey for 48 hours.
Muddle 2 slices of ginger in a mixing tin.
Add whiskey, lime, and simple syrup
Shake vigorously with ice and pour into a copper mug or a large rocks glass.
Top with ginger beer and add pieces of the pineapple that have been soaking in the whiskey to the cocktail.
Garnish with something fun and green.