1/4 teaspoon freshly grated nutmeg, plus more for garnish
1 1/2 cups dark rum
4 cups crushed ice
In a large bowl, combine 2 of the basil leaves with the limes, oranges, orange juice, sugar, chile and 1/4 teaspoon of nutmeg. Using a potato masher or a large wooden pestle, pound the limes and oranges until the sugar is dissolved and a rich syrup forms. Squeeze and discard the lime and orange quarters. Stir in the rum.
Fill 4 large wineglasses or highball glasses with the crushed ice and bury a basil leaf in each. Fill with the rum drink, garnish each drink with grated nutmeg and serve.
The recipe can be prepared through Step 1 and refrigerated overnight.