01 - Place the grated raw potatoes into a clean kitchen towel and firmly wring out as much moisture as possible to ensure crispiness.
02 - In a large mixing bowl, thoroughly combine the squeezed grated potatoes, mashed potatoes, all-purpose flour, baking powder, salt, and ground black pepper.
03 - Gradually stir in the whole milk and the lightly beaten egg until a thick, cohesive batter forms.
04 - Heat 1 tablespoon of unsalted butter and 1 tablespoon of vegetable oil in a large nonstick skillet over medium heat until shimmering.
05 - Working in batches, drop heaping tablespoons of batter into the preheated pan, gently flattening each portion to form individual pancakes.
06 - Cook for 3 to 4 minutes per side, or until each boxty is beautifully golden brown and crispy. Add additional butter and oil as needed for subsequent batches.
07 - Transfer the cooked boxty to a plate lined with paper towels to absorb any excess oil. Serve immediately while hot.