Adapted from kitchendaily.com
cup fresh mint leaves, plus 10 for garnish
cup fresh sage leaf
oz dark rum
Using a muddler or large wooden spoon, mash sugar and herbs together in a large saucepan until the herbs are bruised and fragrant. Add water and bitters; bring to a simmer over medium-high heat, stirring often, about 5 minutes. Stir in rum and cook for 1 minute. Add butter and cook, stirring, until it melts. Strain the mixture into a pitcher. Let stand for about 10 minutes to mellow the flavors. Serve in cordial glasses or other small heat-safe glasses, garnishing each drink with a mint leaf. To Make Ahead: Let cool, cover and refrigerate for up to 1 day. Reheat on the stovetop over low heat or in the microwave on Medium.