Using a box grater or a food processor fitted with shredding discs, grate half of the peeled potatoes using the large holes and the other half using the small holes. Varying the shred sizes creates a contrasting texture: a soft, uniform interior with thin, wispy pieces that fry into extra-crisp edges.

Finely grate or process the yellow onion, dropping the shreds straight into the bowl with the grated potatoes.

Transfer the grated potato and onion mixture into a large colander or a thin linen kitchen towel set over a medium bowl. Let the mixture rest undisturbed for 10 minutes to naturally drain.

Gather the corners of the kitchen towel and twist firmly over the bowl, squeezing aggressively to wring out as much excess liquid as humanly possible. The drier the shreds are before hitting the skillet, the crisper your finished pancakes will be.

Set the squeezed potato and onion mixture aside in a separate bowl. Let the collected liquid sit undisturbed for 5 minutes so the cloudy white sediment can settle to the floor of the bowl.

Carefully pour off and discard the clear surface liquid, leaving the thick, sticky paste of pure natural potato starch anchored to the bottom. Add the squeezed potato and onion mixture directly into the bowl with the starch.

Crack the two large eggs into the bowl, and add the all-purpose flour and sea salt. Stir the mixture firmly with a heavy spoon until the ingredients are completely integrated into a thick, uniform potato batter.

Pour the neutral frying oil into a large, non-stick skillet or heavy cast-iron pan until it forms a thin, even layer across the base. Place the pan over medium-high heat until the oil shimmers and a tiny speck of potato dropped into the pan sizzles instantly.

Working in small batches to avoid crowding the skillet, scoop roughly ¼ to ⅓ cup of the potato batter per pancake into the hot oil. Use the back of your spoon to gently flatten each mound into a round disc roughly ½-inch thick.

Fry undisturbed for 3 to 4 minutes per side. Watch the borders closely; flip the pancakes the exact moment the bottom side takes on a deep, even golden-brown color and the wispy edges look completely crisp.

Transfer the hot potato pancakes to a plate lined with paper towels to drain any pooling surface oils for 1 minute. Repeat the process with the remaining batter, adding a splash of extra oil between batches if the pan looks dry. Serve immediately while hot and crisp alongside a dollop of applesauce or sour cream.