Take a mason jar and clean it carefully. Cut the kumquats into slices and halves (lengthways). Layer the fruit on the edge of the glass (because of the optics) and fill up with the rock candy.
We let the rum flow into the gaps, add a dash of orange aroma (or Grand-Marnier) and then seal the glass airtight. Let it rest for at least four weeks or more.
Put 1 - 2 teaspoons of the rock candy or (if the dissolution process has progressed far enough) the viscous sugar solution in hot tea and stir.
The kumquats give a delicious aroma, but can also be enjoyed in between meals.