I think one of the first frozen foods I had in Japan was frozen onigiri. The hubby bought them one evening and I was skeptical. I don’t really like frozen food and these seemed to simple to be good. I loved them. Haven’t bought them since but they did inspire me to explore the world of yakionigiri. There have been terrible results in the past but now all is good. I haven’t perfected them but they are pretty good. I usually use the frying pan but I tried them in the riceball plates of my waffle iron and was pleased. It’s so easy. Since I need to have some food prepped in the freezer for work day breakfasts, lunches and dinners, freezing riceballs seemed to be perfect. You can just reheat with miso soup for a quick meal. They are best heated in a toaster oven so they don’t get too soggy. I use the grill setting in my microwave but keep the pan on a lower level than when actually grilling.
Basically, lightly salt the rice and make riceballs. If you need a tutorial, check out this one on Just Hungry. In a small bowl mix a bit of soy sauce and grated ginger. Lightly oil a frying pan and heat up the pan on medium. When the frying pan has heated up, place the rice balls and fry until they are just starting to turn golden. Turn over and either brush or sprinkle with a spoon the ginger soy sauce mixture on the cooked side. Just a little at a time so the riceball doesn’t fall apart. When the other side has started to change color turn over again and repeat with the sauce. Now you can fry them until they turn a deeper color. If you are freezing them, cool them completely before putting them in the freezer. Either thaw at room temperature or microwave for about 30 seconds and then put them in the toaster oven until they look nice and toasty.