Make juice from 0.75 oz of rhubarb
Place the rocks ice into the rocks glass
Pour 0.75 oz of rhubarb juice and 0.5 oz of lemon juice into the shaker
Add 0.75 oz of homemade citrus oil and 0.75 oz of amaro
Fill the shaker with ice cubes and shake gently
Strain into the rocks glass
Fill to the top with club soda
Garnish with a lemon wedge and a mint sprig