Comfort food at its finest, potato pancakes make a great accompaniment to roast pork or chicken, especially when served with applesauce. The secret is to make the batter at the last minute and to fry the pancakes in just enough very hot oil so that they get crunchy and golden on both sides. This might not be a side dish that figures on your menu with great frequency, but it is a special treat on a cold wintery evening.
Grate the potatoes using the shredding disk of a food processor or the large holes on a box grater. Using your hands, squeeze the potatoes dry. Place the potatoes and onion in a large bowl. The potatoes will discolor if they are allowed to sit for any length of time, but this is not a problem and won't affect the appearance or taste of the cooked pancakes.
In a separate small bowl, whisk together the flour, baking powder, salt and nutmeg. Add the flour mixture to the potatoes and stir to combine.
Place a large 10 or 12-inch skillet over high heat and add enough oil to completely coat the bottom of the pan. In this case, more oil is better than less. Use two skillets if you have them, rather than cook in batches.
Meanwhile, add the egg and egg white to the potato mixture and stir to combine.
When the oil is hot, spoon dollops of potato batter into the pan, pressing each pancake with a fork into a thin, flat round. You should be able to fit 3 or 4 pancakes in the pan. Keep the pan over medium-high to high heat so that the bottom of the pancakes turns golden brown and crispy, 4 to 6 minutes. Flip the pancakes and cook on the other side until browned, 3 to 6 minutes. Transfer the pancakes to a double layer of paper towels, and pat to remove excess oil. Add more oil and allow the pan to get hot again before cooking a second or third batch of pancakes.
Serve immediately, seasoning to taste with salt and pepper. If desired, serve with Homemade Applesauce (see recipe on this site).