Add all the ingredients to a shaker filled with pebble ice, then shake until chilled. Pour into a chilled glass and garnish.
Coconut-Lychee Milk
In a blender, add two 13.5-oz. cans of coconut milk, 1 lb. of peeled fresh lychees (canned also works), 2 Tbsp. of freshly grated ginger, the zest and juice of 1 lime, 1 Tbsp. of Jamaican rum, 1 tsp. of vanilla extract, and 1 tsp. of kosher salt, and blend until smooth. Pour the mixture into a large zip-sealed plastic bag and cook with a sous vide at 120 degrees for 30 minutes, then remove the bag and fine strain the liquid. (Alternately, simmer the mixture in a pot for 30 minutes, then fine strain the liquid.) Store refrigerated in a sealable container for up to 2 weeks.
Salted Pistachio Syrup
Toast 1/2 lb. of roughly chopped raw pistachios in a pot over high heat, stirring until fragrant. Add 2 cups of water and 2 cups of sugar to the pot and stir until the sugar dissolves. Reduce the heat to low and let simmer for 10-15 minutes, then remove from the heat and let cool. Pour the mixture into a sealable container, then cover and refrigerate for 2 days. Fine strain the syrup and stir in 2 1/4 tsp. of kosher salt. Keeps refrigerated for up to 4 weeks.