Shake everything but the sparkling water with ice, and strain into a narrow Collins glass. Stir the drink and slowly add half of the sparkling water; after some agitation, the froth should creep up to the top of the glass. If it doesn’t, add a little more and keep stirring. Let it rest for 15-20 seconds, and then slowly pour in the rest of the sparkling water to lift the foam above the edge of the glass. Serve with a straw.