Master mixologist Erick Castro of San Diego’s Polite Provisions tinkered with the typical Piña Colada recipe, adding ever-greater shares of Green Chartreuse to get more of its complex, herbaceous flavor. Eventually, he ditched the rum entirely and maxed-out the Chartreuse, tinkering with the recipe until he landed on this recipe for the Piña Verde.
It’s difficult to specify how much ice should go into a blended drink; much depends on the type of ice you use, the style of blender, and so on. Start with about a cupful of ice for each serving, and add more ice, a half-cup at a time, until you’ve achieved a thick mixture that can’t quite hold a spoon upright.