Wilt the spinach in a dry hot pan for 1 minute, then tip into a sieve and press out the liquid firmly.

Beat the eggs with salt and pepper until just uniform.

Melt the butter in a non-stick pan over medium-low heat and pour in the eggs.

As the edges set, drag them to the centre with a spatula and tilt the pan so raw egg runs into the gap. Repeat for about 90 seconds.

When the surface is still slightly glossy, scatter the drained spinach and crumbled feta over one half.

Fold, slide onto a plate, and let the residual heat finish it.