You can make this in no time whenever you want. This recipe doesn't generate leftover egg whites. It comes in handy when you want to make custard cream right away.
I make this custard cream whenever I need it for another dessert. It's troublesome to separate eggs, so I use egg whites as well.
There are no special hints. I place a pot on a scale and I even weigh milk to make it quickly.
Enjoy Japanese food around the world.