In a medium bowl, vigorously whisk together the eggs, buttermilk, and cornstarch. Continue whisking until the mixture is frothy and full of air bubbles.

In a skillet set over medium-low heat, melt the butter, swirling it around to evenly coat the surface of the pan.

Pour the egg mixture into the skillet and let it sit undisturbed for a few seconds to allow the bottom to begin setting.

Using a spatula, gently drag through the center of the eggs to expose the bottom of the skillet. Let the uncooked egg mixture flow into the exposed area. Repeat this motion in different directions, allowing the eggs to gently set while staying soft and creamy.

Once the eggs are mostly cooked and no longer appear runny, remove the skillet from the heat. The residual heat will finish cooking the eggs.

Season with kosher salt and freshly ground black pepper to taste. Serve immediately.