Peel the potatoes and cut into 1/4. Put some water and the potatoes in a pot and boil until get soft enough to be mashed.

Place the drained potatoes to a bowl and mash them. Add the cornstarch, water and salt and mix well.

Devide the potato mixture into 6 balls. Poke deep hole in each ball and fill each with the cheese. Mold the potato around cheese to enclose. Flatten each filled potatoes to 3/4 inch thick.

Melt the butter in a pan on low heat, place the potato cakes to the pan and cook both sides on medium heat until golden browned.