2 teaspoons potato starch, tapioca starch or cornstarch
4 tablespoons cold unsalted butter, cut into 1/4-inch cubes
4 eggs (see Note)
Pinch of kosher salt
In a medium bowl, whisk together starch with 1 1/2 tablespoons water until no lumps remain. Add half the butter cubes to starch mixture. Add eggs and salt, and whisk, breaking up any cubes of butter that have stuck together, until the eggs are frothy and homogenous. (There will still be solid chunks of butter in the eggs.)
Set your serving plate near the stovetop. Heat 1 tablespoon water in a 10-inch nonstick skillet over medium-high, swirling gently until the water evaporates, leaving behind only a few small droplets. Immediately add the remaining 2 tablespoons butter and swirl vigorously until the butter is mostly melted and foamy but not brown, about 10 seconds.
Immediately add the egg mixture and cook, pushing and folding the eggs with a spatula, until they are slightly less cooked than you’d like them, about 1 to 2 minutes, depending on doneness. More vigorous stirring will result in finer, softer curds, while more leisurely stirring will result in larger, fluffier curds. Immediately transfer to the serving plate, and serve.
If cooking fewer eggs or more, adjust pan size accordingly, and note that cooking time in Step 3 can vary significantly, needing as little as 15 to 30 seconds for 2 eggs, or as long as 3 to 4 minutes for 8 eggs.