Into a large teapot or heatproof pitcher, pour 6 cups boiling water over mint leaves. Allow to steep 3 to 4 minutes.
Meanwhile, in each of 8 mugs or Irish coffee glasses, use a wooden spoon to mash 3 fresh mint leaves with 2 tsp. sugar and 1 tsp. lime juice.
Add 1/4 cup (2 oz.) light rum and 3/4 cup of the mint tea, poured through a strainer, to each. If you like, you can garnish with a few fresh cranberries for Christmas red and green.
Note: Nutritional analysis is per serving.