This was the most popular recipe at home when I was growing up. It was a standard dish for breakfast and in bentos. It's quite plain, but it's a flavor you'll want to keep coming back to.
This is my mother's flavor. I hope I've recreated it faithfully enough...
In Step 2, if you want to get rid of the fat that comes out of the meat, you can wipe it out of the pan with paper towels. This can be frozen and stored.
Enjoy Japanese food around the world.