Add all ingredients into a shaker, add ice, and shake vigorously.
Strain ice and shake again. (This step is to aerate the drink further for best foam.)
Strain into rocks glass with one large cube.
To garnish, squeeze the oils from a lemon peel onto the top of the drink, then toss it
Carefully place five drops of the bitters around the edge of the glass, then use a sharp point to gently draw a circle around the drink in order to smear the drops to get the look of an intricate design.
