Muddle mint leaves. Add lime, gin, and ice and shake. Double strain into Collins glass over serving ice. Add ginger beer and gently stir. Garnish with mint.
Original calls for 0.75 oz "Merchant's Exchange Moscow Mule Mix" combined with 2 oz soda water, but suggests ginger beer as a substitute for the combination if unobtainable.
New Orleans Magazine, March 2021, p. 58