From Mimi Sheraton, originally
2.5 lb Eastern All Purpose Potatoes
1.5 lb (give or take) onions
2 eggs, separated
2 tablespoons potato flour or matzoh meal (I always use matzoh meal)
1 scant tablespoon salt
1 tsp white pepper (I use a generous pinch)
Corn oil for frying
When I was young, we grated the potatoes and onions together on a box grater, leaving behind some skin from the knuckles every year. "It's not the same without the blood," we'd say, although nobody was fooled that the blood was truly necessary for taste. In the dawn of the food processor age, we were very excited about the speed with which the grating could now (we thought) be accomplished, except that it turned out that grating potatoes in the food processor produced a product more like hash browns, and less like what we loved and wanted. So we continued on with the box grater for several more years until I went to college and met Birgit. Birgit, who is of German descent, also grew up with potato pancakes, although not quite the same recipe or flavor. Her mother, it turned out, had discovered that you could use a blender on the potatoes to achieve a quite satisfactory result. Although we later concluded that using a blender is too slow to make more than 4-5 people's worth at a time, the idea that you would quasi-puree the potatoes provided the enlightenment necessary to devise the two-step food processor method. In this method, the potatoes are first shredded, then the shreds are processed with the steel blade into a very coarse mash. If the shredding step is omitted, the result (by the time an even texture is achieved) is a puree that is much finer than desired and makes an oddly textured pancake.
Wash and peel the potatoes. If they are peeled a significant time in advance they should be placed in cold water; otherwise they need not be. Peel the onions. Cut both the potatoes and onions into coarse chunks, and process with the shredding blade of a food processor, combining some potato and some onion in each hopper-full. When the bowl is full, transfer the shreds to a separate bowl temporarily and change the shredding blade for a steel blade. Place half the shreds back in the bowl, and process until a coarse mash is achieved. Transfer this mash to a fine-mesh strainer over a bowl, and process the second half of the shreds. While the mash is draining, replace the shredding blade and continue processing; when a new batch of mash is generated place the mash from the first batch into a large bowl that will hold the final batter. Continue in this fashion until all the potatoes have been processed. When the final batch of mash is generated, leave it to drain while the rest of the batter is prepared.
Add the egg yolks, salt, matzoh meal, and pepper to the bowl of potato mash. Beat the egg whites until stiff. Add the last batch of mash to the bowl, then pour off the liquid and recover the potato starch that has gathered under the draining mash; add this to the batter as well. Mix together thoroughly, then fold in the egg whites.
Add enough oil in the bottom of a skillet so that the pancakes will be able to just float, and heat until the oil crackles when a few drops of water are flicked into it. Fry pancakes until golden brown on each side.