Add the first 4 ingredients to a shaker with ice. Shake until chilled, then strain into a glass over fresh ice. Add the tonic, top with pebble ice, then drizzle the blue Chareau on top. Garnish.
Blue ChareauAnd 1/8 tsp. of blue spirulina to 1/2 cup Chareau and whisk. Will keep in the refrigerator for 2 weeks.