01 - Place the potatoes in a pot of cold, salted water. Bring to a boil, then simmer for 10–12 minutes until completely tender. Drain well and mash until smooth.
02 - While the potatoes are still warm, mix in the butter and milk until creamy. Allow to cool slightly.
03 - Stir in the sliced scallions, flour, salt, and pepper. Mix until a soft, slightly sticky dough forms.
04 - On a floured surface, turn out the dough and gently knead. Pat or roll into a 1/2 inch thick round. Cut into 8 rounds or triangles.
05 - Dust each cake lightly with flour.
06 - Heat oil or butter in a large nonstick skillet over medium heat. Fry the potato cakes in batches for 3–4 minutes per side, or until golden and crisp.
07 - Serve warm, garnished with extra scallions or butter if desired.