Prep Glass: Fill a Rocks glass with ice. Give it a quick stir and set it aside.
Add Bitters: Pour 2 dashes of lemon bitters into the shaker.
Add Syrups: Add ⅓ oz ginger syrup and ⅓ oz honey syrup.
Add Rosemary: Drop 1 fresh rosemary sprig into the shaker.
Muddle: Using the muddler, muddle the rosemary sprig well to release its aroma.
Add Lemon Juice: Add ¾ oz fresh lemon juice into the shaker.
Add Chartreuse: Measure and pour ½ oz Yellow Chartreuse into the shaker as well.
Add Bourbon: Finally, add 1½ oz Bourbon to the mix.
Shake Well: Fill the shaker with ice, close it and give it a good shake (10-15 seconds).
Strain: Discard the ice in the Old Fashioned glass and refill it with fresh, new ice cubes. Then, use both the cocktail strainer and the fine strainer to strain the drink into the ice-filled glass.
Garnish: Garnish with a rosemary sprig (you can slightly burn it before for a smoky & herbal scent) and serve immediately.