01 - Place the grated raw potatoes in a clean tea towel and squeeze out as much moisture as possible.
02 - In a large bowl, combine the grated raw potatoes and mashed cooked potatoes.
03 - Add the flour, baking powder, salt, and black pepper. Mix well.
04 - Gradually stir in the milk to form a thick, slightly lumpy batter.
05 - Heat 1 tablespoon butter and 1 tablespoon oil in a large nonstick skillet over medium heat.
06 - Drop large spoonfuls of the batter into the pan, flattening gently to form pancakes about 1/2-inch thick. Cook for 3-4 minutes per side, until golden brown and crisp. Repeat with remaining batter, adding more butter and oil as needed.
07 - Drain pancakes briefly on paper towels. Serve hot, topped with a dollop of sour cream and a sprinkle of chives if desired.