The key is to heat the milk and the black tea together. You can easily make this in a mug. It's also delicious made with half hot water and half milk.
I didn't like the idea of putting the tea bags in the microwave with the staples attached, so I decided to do it this way.I also find wrapping the teabags up with their string somewhat relaxing.
Mind you don't prick yourself when you are removing the staples from the tea bags.
Enjoy Japanese food around the world.