Chef John's Crispy Potato Pancakes

Combine diced potatoes and chopped onion in a large container, then add sufficient cold water to cover the mixture by several inches. Allow the potatoes and onion to absorb the water for 20-30 minutes, permitting them to become thoroughly saturated.

Transfer the potato mixture to a colander and rinse it under running water, followed by draining the liquid and squeezing the potatoes repeatedly to remove all excess moisture.

In a separate bowl, blend eggs, flour, salt, black pepper, and cayenne pepper until they form a smooth, uniform mixture.

Combine the potato mixture with the egg mixture in a large bowl using a spatula, ensuring they are well incorporated.

Heat 1/4-inch of oil in a heavy skillet over medium-high heat. When the oil reaches its shimmering point, carefully drop large spoonfuls of potato batter into the hot oil and flatten them with a spatula to about 1/2-inch thick. Cook until the edges of the pancakes are golden brown and crispy, taking around 3-5 minutes.

Decrease the heat to medium, flip the pancakes, and cook until they are golden brown and crispy on the other side, approximately 5 minutes more. Repeat the cooking process with the remaining batter.