Melt a half-teaspoon of butter in a sizable cast-iron or nonstick skillet over low heat until it begins to froth.
Add the eggs and finish with a few grinds of black pepper and a pinch of kosher salt. Cook for 2 to 3 minutes, or until the yolk is still runny but the white is firm. To fully cook the yolk, flip the pan over and cook it for a further two minutes. Make sure the yolk is broken by giving it a gentle push with a spatula after one minute.