From the Wikipedia entry on East Frisia:
In an otherwise coffee drinking country, East Frisia is noted for its consumption of tea and its tea culture. Strong black tea is served whenever there are visitors to an East Frisian home or other gathering, as well as with breakfast, mid-afternoon, and mid-evening. Tea is sweetened with kluntjes, a rock candy sugar that melts slowly, allowing multiple cups to be sweetened.2 Heavy cream is also used to flavor the tea. The tea is generally served in traditional small cups, with little cookies during the week and cake during special occasions or on weekends as a special treat. Brown rum, mixed with kluntjes and left for several months, is also added to black tea in the winter. The tea is alleged to cure headaches, stomach problems, and stress, among many other ailments."
As for me, I had a pot of it this morning with breakfast: it is an ideal blend for that time of day. But I couldn’t abide sweetener or cream, so I had it black. It was delicious! Perhaps if I ever travel to Ostfriesland, I shall try it the traditional way