Stir, strain, up. Coupe, chilled.
The Bolivar bitters present cassia, chamomile, and dried fruits. Orange bitters might work as a substitute. Avoid Angostura and the like.
Had an open bottle of tawny. Seemed like it would be fun to pair with Cynar. Whereas sweet vermouth comes across as bitter, sweet, and spiced, the tawny port was more acidic and 'livelier'.