This is a small dish I made from the steamed spinach my wife made. She cooked the entire bag of spinach (pre-washed) using a dry wok with a lid without any liquid. We kept this in a sealed container and used it for many dishes such as this one.
This is a variation of nori rolled spinach but instead, of using nori I used a thin omelet.
Spinach: I just seasoned the steamed spinach with Japanese prepared hot mustard (from a tube) and sugar mixed in some soy sauce (the amount is arbitrary, I use only small amount of sugar). If you want it spicier you could increase the mustard. I also mixed in bonito flakes but this is optional especially if you want to keep it vegetarian.
Omelet: I made the mistake of not watching it carefully and the flame was too high so it became a bit dry and browned. I just used one egg omelet seasoned with a bit of sugar and salt. I put a non-stick frying pan on low flame ( not low enough, apparently) poured in the egg mixture, put the lid and let it slowly cook until done (5-7 minutes). If the flame is low enough, the omelet is perfectly yellow without brown spots.
I placed the omelet on the cutting board and lined up the spinach mixture in the middle and rolled it up. I then rolled it in plastic rap and let it stand for a few minutes so that the omelet would not unravel. I then cut the roll into small disks as you see above, Both ends which are not perfect were eaten before serving by me and my wife.
This is nothing dish but quite good.