Preheat. Preheat your oven to 300°F (148.9°C). Take a sheet pan, put a rack over it, and put it in the oven. This is used for draining and crisping the pancakes and keeping them hot when they come out of the oil.
Prep the binder. Crack the egg into a large mixing bowl, and beat it lightly with a fork or whisk. Add the flour, baking soda, salt, pepper, and stir together with the fork. Don't worry if there are lumps.
Tater time. Peel the potatoes. Now shred them with the big holes on a box grater or a food processor. We are now going to try to get as much moisture as possible out of the potatoes. Nothing works better than squeezing the shreds in a potato ricer. Don't worry, it won't push them through the holes. If you don't have a ricer pick up a small amount of the grated potatoes and, over the sink, with your hands, squeeze out as much water as possible. Repeat. Then spread the grated potato mix out on a double layer of paper towels, cover with another double layer of paper towels, and press hard. Another method is to put the potatoes into the center of a few layers of cheesecloth, a clean T-shirt, or a clean kitchen towel, pull together the edges making a pouch, and twist and squeeze out as much moisture as possible. Add the potatoes to the bowl with the egg mixture, and stir gently until the potatoes are all coated. Chop and mix in the onions.
Fry. Pour enough oil into the pot to cover the bottom about ¼ inch deep. You don't want to totally submerge the patties so steam can escape the side above the surface. More importantly, you want the potatoes in contact with the bottom because hot metal conducts more heat that hot oil. Heat the oil to about 375°F (190.6°C). Get it all the way up there because the cold potatoes will cool it off quickly.
Patty time. One at a time, make patties about 3 inches (76.2 mm) across and about 1/2 inch (12.7 mm) high, but leave the edges jagged. An ice cream scoop is a good measuring device. Ease the patties into the oil one at a time about a minute apart, being careful not to splash. Flatten them immediately so they aree about 1/2-inch thick. You should be able to fit four into a 12 inch (304.8 mm) pot at a time, and they should not be touching much. The reason to stagger their start time is to keep the oil temperature hot. If you add four at a time, the oil temp will drop and the pancakes can get soggy. When you add the last one, you should notice the edges of the first one are getting golden after 5 to 7 minutes. Check the bottom of the first patty by lifting it with a slotted spatula. It should be golden, but there still may be milky parts showing. Flip it when it is completely golden. It is easiest with two spatulas or a spatula and a large spoon so they don't splatter or break. Flip the patties away from you so they don't splash. Cook another 3 to 4 minutes on the second side until golden. Remove the patty and gently put it on the rack over the baking pan in the oven to crisp even more and to make sure the center is cooked through. Leave them in the oven for about 10 minutes to drain, crisp, and be sure the centers are cooked.
Treats! When they are all done, scoop out the bits that are left behind in the oil, drain, cool, and eat them yourself. Cook's treat!
Serve. After they have been in the oven for about 10 minutes the latkes will darken a bit, crisp even more on the outsides, and cook thoroughly through the center. Sprinkle lightly with large grain salt and serve hot. Some folks like to place a dollop of apple sauce or sour cream on them. L'chiam!