01 - Grate the starchy potatoes on a box grater. Place in a clean kitchen towel and squeeze out as much moisture as possible.
02 - Boil the waxy potatoes in salted water until tender, about 10-12 minutes. Drain thoroughly and mash until smooth.
03 - In a large bowl, combine the grated raw potatoes, mashed potatoes, milk, melted butter, and egg. Mix until well incorporated.
04 - Add the flour, baking powder, salt, and pepper. Stir to form a thick, homogeneous batter.
05 - Gently fold in the sliced scallions until evenly distributed throughout the batter.
06 - Heat a large skillet over medium heat and add 1 tablespoon of butter or oil.
07 - Drop ¼-cup portions of batter into the pan, flattening each to approximately ½ inch thickness.
08 - Cook for 3-4 minutes per side until golden brown and crispy. Add more butter or oil as needed between batches.
09 - Serve hot, garnished with additional sliced scallions if desired.