Peel the lemons using a very sharp knife, taking care to avoid the white pith, which is somewhat bitter.
Chop the peels and add them to a large heatproof bowl.
Measure the sugar onto the lemon peels and using a fork or potato masher, mash the peels and sugar together.
Boil 1 quart of water in a large pot and add the tea bags.
Allow the tea to steep for about 5 minutes and then remove the bags.
Pour the tea onto the sugar/peel mash-up. Stir until all the sugar is dissolved.
Add the lemon juice. The 4 lemons should come close to the full amount – add more as needed.
Add the Cognac and dark rum.
Stir until the liquids are thoroughly blended.
Place in the refrigerator for at least 1 hour.
When you’re ready to serve it, pour the mixture into a punch bowl, add ice to fill, and grate nutmeg on top.