Heat a clean 20–25cm non-stick frying pan over a medium–low heat.
Add 15g unsalted butter to the warm pan and swirl to coat the base; heat until it shimmers but does not brown.
Crack 2 large eggs directly into the pan, keeping them apart (or crack them into a bowl first and gently slide them in).
Let the eggs cook undisturbed for 2–3 minutes, until the whites are mostly set and opaque but the yolks remain runny.
Use a thin, flexible spatula to gently flip each egg in a swift motion.
Cook for a further 30 seconds to 1 minute, until the thin white film over the yolk turns opaque but the yolk stays runny.
Slide the eggs onto a plate and immediately season with a pinch of salt and black pepper.