Simple switch of Italian Vermouth replaced by Amer Picon and the strength dialled up from the classic Negroni/Boulevardier 1:1:1 ratio. Dark and sultry. Flaneur means an idler, someone who wanders aimlessly related to the Boulevardier, man about town.
25ml Amer Picon
Stir with a large ice cube and express orange zest over.