Whisk the flour, eggs and milk together with a pinch of salt until you have a smooth batter the consistency of single cream.
Stir in the melted butter, then leave the batter to rest for 10 minutes while you heat a frying pan over a medium heat.
Brush the pan with a little butter and pour in a ladle of batter, swirling the pan so it coats the base in a thin layer.
Cook for about 1 minute until the underside is golden, then flip with a spatula and cook the other side for 30 seconds.
Slide onto a plate, squeeze over lemon and sprinkle with sugar, then repeat with the rest of the batter. Stack the pancakes up as you go.