Put the gelatine in cold water. Rub the zest of 2 limes with a fine grater. Squeeze half a lime
Carefully bring the cream with the sugar, the juice of half a lime and the grated zest of the 2 limes to the boil, stirring constantly. Also works great with a food processor with a heating function.
Remove the pot from the oven. Take the gelatine leaf out of the water and squeeze it out gently so that it releases the water. Add the gelatine leaves and rum while stirring. Stir everything together for approx. 1 - 2 minutes without heat. Divide the mixture into 6 small glasses.
Put in the refrigerator for at least 5 hours, but preferably overnight. Garnish with a mint leaf to serve