01 - Wrap grated raw potatoes in a clean kitchen towel and squeeze firmly to extract excess moisture until potatoes feel dry to the touch.
02 - In a large mixing bowl, combine squeezed raw potatoes with cooled mashed potatoes. Mix thoroughly until evenly distributed.
03 - Sprinkle flour, baking powder, salt, and pepper over potato mixture. Stir well to incorporate all dry ingredients evenly.
04 - Gradually pour milk into bowl while stirring. Mix until thick batter forms with small lumps remaining—do not overmix.
05 - Melt 1 tablespoon butter with 1 tablespoon oil in a large nonstick skillet over medium heat. Swirl to coat bottom evenly.
06 - Drop generous spoonfuls of batter into hot pan. Gently flatten with back of spoon to create 1/2-inch thick pancakes.
07 - Fry pancakes for 3 to 4 minutes until edges set and bottoms turn deep golden brown. Adjust heat if browning too quickly.
08 - Carefully flip pancakes. Cook second side for 3 to 4 minutes until golden and crisp throughout. Add remaining butter and oil between batches as needed.
09 - Transfer cooked pancakes to paper towel-lined plate to drain briefly. Serve immediately topped with sour cream and fresh chives.