1. Crack the egg into a small bowl and set it aside. Then, place a non-stick skillet over medium-low heat and melt the butter till it bubbles.
2. Transfer the egg into the skillet, careful so the yolk remains intact, and cook for one to two minutes. You want the white to turn opaque with a set yolk.
3. Sprinkle the egg with pepper and salt, then slide it from the pan to the plate and serve.

This video can also help you with how to cook sunny-side-up eggs.