Melt the butter in a nonstick skillet over medium-low heat.
Crack the eggs into the pan, leaving space between them. Cook for 2–3 minutes, until the whites are set and no longer clear.
For sunny-side up, cover the pan for the last 30–60 seconds so the top of the whites sets, then slide the eggs onto a plate.
For over easy, gently flip each egg with a thin spatula and cook for 30 seconds more. Cook for 1 minute for over medium or 2 minutes for over hard.
Season with salt and pepper and serve right away.