Add the potato starch, butter, water, nori flakes, and salt; mix until smooth.
Using an ice cream or measuring scoop, scoop the “potato dough”, and flatten in your palm. Place the mozzarella cheese piece into the center and wrap the potato dough around the cheese. Pinch together the seams together. Repeat with remaining potato dough.
Place a frying pan over medium high heat and add vegetable oil. Place the potato balls into the oil, and shallow fry until golden brown, 8-10 minutes. Make sure to flip halfway through.
Once the potato cutets are ready, remove from the pan. Set aside on a paper towel.
SAUCE
In a small pan, combine all the ingredients for the yaki sauce. Bring the mixture to a simmer over medium heat. Allow it cook, stirring occasionally, until the sauce is slightly thickened and glossy (some people prefer to thicken until it gets sticky. I prefer slightly thick saucy consistency.).
FINISH
Brush the yaki sauce onto both sides of the patties. Wrap the potato mochi with a strip of nori. Enjoy hot!
Notes
If you don’t have potato starch, you can use corn starch without any issues.The exact number of imomochi you’ll make will depend on the size of the scoop you use. 10-12 is the average for me.