Clean the potatoes and cook them using your preferred method, whether baked boiled, or microwaved.To microwave, simply place the potatoes in the microwave and cook on high for about 8 to 10 minutes, flipping mid way through cooking. The potato is cooked when a fork or skewer can easily pierce through the thickest part of the potato.

If baked or microwaved, cut the potato in half, then scoop out the flesh into a mixing bowl. The potato will be super hot, so let it cool a little if needed and be very careful! If boiled, make sure to completely drain the potato before transferring into a mixing bowl.

Add the butter to the mixing bowl with the cooked potato and mash together with a fork or a potato masher until well combined.

Then, add the potato starch and mix until smooth and no more dry starch is visible. The dough should be able to be balled up and hold its shape nicely, but it should not be sticky.

If stuffing with cheese:Divide potato dough into 4 portions. Ball up a portion of the potato dough, then flatten it in your palm. Place the cheese in the center and wrap the dough around the cheese. Pinch together the seams and any cracks. Shape into a 2 to 3 inch wide patty. Repeat with remaining.If making plain ones without cheese:Divide potato dough into 5 portions. Ball up a portion of the potato dough, then gently flatten it into a 2 to 3 inch patty in between your palms. Pinch together and smooth out any cracks. Repeat with remaining dough.

In a medium or large nonstick pan over medium heat, add enough oil to cover the bottom of the pan. Once the oil is hot, gently place the patties into the pan and pan fry each side until golden brown, about 3 to 4 minutes per side.

Option A:Mix together all the ingredients for the yaki sauce (soy sauce, mirin, sugar). When the potato mochi patties are done pan frying, move the patties to one side of the pan and soak up all of the excess oil with a paper towel. Pour the prepared yaki sauce in the pan and bring to a simmer. Allow the potato patties to simmer in the sauce, flipping once or twice, until the sauce thickens and looks glossy.

Optional B:Once the potato patties are done pan frying, remove them from the pan and let them drain on some paper towels or a rack.Into a small pan, combine all the ingredients for the yaki sauce (soy sauce, mirin, sugar). Bring the mixture to a simmer over medium heat. Let it cook for until the sauce looks slightly thickens and looks glossy. Stir occasionally.Brush or drizzle all of the the yaki sauce onto both sides of the potato mochi patties.

Wrap the potato mochi with a strip of nori and enjoy while hot!