1. In a skillet, heat 1 tbsp vegetable oil and fry garlic until fragrant. Add onion, coriander and cook until wilted. Add ingredients "A" to season and fry for a few more minutes. Let it cool and set aside.
2. Once they have cooled down, transfer into a medium bowl and add ground beef. Mix well. Add ingredients "B", mix and knead well using your hand until it becomes smooth and elastic.
3. In a separate bowl, add cooked japanese rice, mayonnaise, and salt and mix well. Using lightly wet hands, form into balls.
4. Grab a handful of the meat mixture, form each piece into a small bowl shape, then flatten it a bit. Place the cooked Japanese rice ball inside and fold the meat around it.
5. Heat 1 tbsp vegetable oil in a saucepan, fry the beef rice balls on both sides until nicely brown or until cooked through.