Soak the rice in the usual amount of water for about 30 minutes. Add a pinch of salt and cook the rice. Wash the shiso leaves and pat dry. Combine the A. ingredients together.
When the rice is cooked, mix in the toasted sesame seeds, and make 10 cylindrical rice balls. (Each one weighs about 60 g.)
Wrap each rice ball with shiso leaves, then wrap the meat around to fix the shiso leaves in place. Finally wrap the meat around the sides of the rice ball too.
For the 2nd slice of meat, change directions and wrap around the rice balls. The key is to wrap up the rice ball completely so no rice is peeking out.
They look like this when all wrapped up.
Line up the wrapped rice balls in a heated frying pan with the seam sides down. Pan fry over medium heat.
When the bottom side is browned, turn the balls to brown on all sides. When they are all browned, wipe out any excess fat in the pan.
Pour in the A ingredients. Shake the pan around over medium-high heat to coat the rice balls with the sauce and evaporate the moisture to finish.
Please see the Nobunaga Oda inspired sister recipe, "Chicken Nanban Marinated in Red Wine" (Recipe ID: 1222637).
(Recipe ID: 1577346) is the recipe for the tamagoyaki (omelette) pictured with the meat wrapped onigiri.
Story Behind this Recipe
This is an original recipe I made based on an onigiri lunch sold at a certain convenience store chain. If you didn't have a chance to have those convenience store onigiri (they were time and region limited), please get a taste of them with this version.
I used 20 pork belly slices that were 2 cm wide and 30 cm long. I used 2 slices per onigiri. Wrap up the onigiri so that you can't see the rice - this is the key to preventing the balls from falling apart while cooking.