Step 1

Preheat oven to 300°F. Place a few layers of paper towels on a large plate. Line a large sheet pan with parchment paper. Set the plate and sheet pan aside.

Step 2

Peel potatoes and cut into large chunks. Quarter onion. Using a food processor fitted with a shredding disk or the large holes on a box grater, grate potatoes, then onion.

Step 3

Set a mesh colander into a large bowl (if you don’t have one, line the bowl with a clean tea towel). Transfer grated potatoes and onions to the colander (or the towel). Remove any large bits of potato or onion that have slipped through the grater. Press on mixture with back of a spoon or clean hands to remove as much liquid as possible. (Alternatively, you can gather up the tea towel, twist the bundle, and squeeze out the liquid.)

Step 4

Empty the liquid from the bowl (if you see white residue in the bottom of the bowl, keep it — it’s potato starch, and will help bind the latkes!). Place the shredded potatoes and onion in the bowl. Add egg, flour, and salt. Mix well.

Step 5

Set a large, heavy cast-iron or nonstick skillet over medium-high heat. Add about 1/4 inch of oil and warm until the surface shimmers and a drop of potato mixture sizzles. Carefully add a heaping Tbsp. or two of potato mixture to the hot oil for each latke, taking care not to crowd the pan. Flatten slightly into pancakes with the back of the spoon; latkes that are too-dome shaped won’t have time to fully cook in the center. (You should be able to fry 3 to 4 latkes at a time, depending on the size of your pan.)

Step 6

Let latkes cook undisturbed until the bottoms turn golden brown, 3-5 minutes, then turn them over. (If oil starts to smoke or potatoes brown very quickly, reduce the heat a little to allow center of latkes to cook through.) Cook until the latkes are crisp and golden on the second side, another 3-5 minutes. Transfer the batch to the paper towel-lined plate to drain. Then move the latkes to the sheet pan and keep warm in the oven while you make the rest of the latkes. To avoid a burnt and bitter taste in the next batch, remove any crisp bits of potato that are swimming around in the oil before adding more mixture.

Step 7

Give potato mixture a quick stir and replenish the oil between batches as needed, making sure it’s hot before adding more potato mixture to the pan. Serve hot latkes with applesauce and/or sour cream.