If you happen to have Gyokuro or high-quality Sencha, both of which has a lot of umami in, why don’t you make tea using ice cubes?? This is how it is prepared.
First, place tea leaves in a small tea pot and put some ice cubes over the tea leaves in it. All you have to do is just wait until ice cubes melt. Now, tea is ready. Isn't that simple? No need to boil water and worry about steeping time. Remember, just wait!
Tea with lots of umami is recommendable for this ice cubed-tea. Enjoy!