Co-founder and general manager of the two outlets Piero Marongiu also supervises the bar's mixology, and says that because Pisco comes in several different styles - sweet and dry, aromatic and non aromatic - it can substitute for a range of other spirits in classic cocktails, but that the favourites at the bar are the Pisco Sour, made with lemon juice and egg white, the Pisco Punch, made with pineapple juice, and his own creation, the Jolly Roger.
"Pisco is a colourless grape spirit which you could call a brandy," Marongiu explains.
"For the Jolly Roger I use a Pisco made from the quebranta grape, which is a non-aromatic variety, because the cocktail already has a lot of aromas from the fruit. We wanted something a little spicy so we did a mix of berries and red chilli pepper," he says.
"You want a sweet and sour mix, so we add fresh lemon juice as well as a dash of sugar syrup," he explains.
To add a finishing sparkle to the drink after double straining it into a chilled Martini glass - the bowls of the Roger Room's martini glasses are set off-centre - Marongiu tops it up with a Brazilian Methode Champenoise sparkling wine.
You could substitute your own choice of Pisco or fizz.