Sift the flour and the salt into a large mixing bowl. Add the eggs and half of the milk and beat with a whisk until you have a smooth batter. Pour in the rest of the milk and beat again until smooth. Cover the bowl with cling film and leave the batter to stand for 30 minutes.
Heat the butter in a 20 cm diameter frying pan and add a ladle of batter. Turn the pan around so that the whole bottom is covered.
Cook the pancake over medium heat for 2 min. until the top is dry and the bottom is golden brown. Turn the pancake over and fry for another 1 min. Repeat with the rest of the batter. Keep the pancakes warm under a lid or a plate until all the batter has been used.