At Caffé Vittoria in the North End of Boston, a drink arrives in a conical glass, a scoop of pistachio ice cream melting into the light green liquid. Served with a demitasse spoon, its taste falls somewhere between dessert and a boozy cocktail.

Recipe: Pistachio Martini

It’s the pistachio martini, beloved in this part of the city, where chalkboard signs spill onto the street announcing its presence on menus. But scratch below its frothy surface and what emerges are more questions than answers — not to mention a healthy dose of skepticism from cocktail snobs. What is a pistachio martini? Why are there so many versions? And why is something that effectively tastes like melted ice cream so popular?

In the North End, bartenders are quick to credit the drink’s popularity in the heavily Italian American neighborhood to its connection to Italy.

But pistachios aren’t Italian.

They actually originate in the Middle East, and, although it’s a popular flavor in Italy and Sicilian pistachios are highly prized, Italy isn’t one of the nut’s top growers: Iran, Turkey and the United States all produce more.