Step 1Chop the onion in a small dice using a food processor. Remove the knife blade, insert the shredder blade and grate the potatoes. Immediately transfer the potato and onion mixture to a large bowl and add the lemon juice, eggs, flour, baking soda, salt and pepper to taste. Mix well.
Step 2Heat 1/8 inch of oil in a nonstick skillet over medium heat. Stir the batter well. Spoon about 1/3 cup of batter at a time into the hot oil and flatten with the back of the spoon to make 2-to 3-inch latkes. Cook on one side until golden brown, 3 to 5 minutes; then turn and cook on the other side, about 2 minutes. (Turn only once.) Drain the latkes well on paper towels. Continue until all the batter is used up. You may have to add a little more oil to the skillet toward the end. Scoop any stray potato pieces out with a fork as you go so they don't burn. Serve immediately.