Build

30 ml Absente
10 ml Grenadine
Cold water to top (about 150 ml)
Garnish: none — the louche is the show

Method

Pour the absente into a tumbler (or aperitif glass). Add the grenadine — it sinks to the bottom in a ruby pool. Top slowly with very cold water (5:1 water-to-absinthe), watching the green louche bloom. Serve without ice — chilled glass and chilled water are enough.