Place a large mixing bowl on a damp cloth to stop it slipping and moving. Sift in the flour and salt into the bowl.
Whisk in the egg and egg yolk and mix in the milk, pouring it in a slow, constant stream.
When it has achieved the consistency of thin cream, stop adding any more milk and whisk in the butter.
Brush a hot non-stick frying pan or crepe riddle with clarified butter. Using a ladle add a little batter to the pan whilst gently twisting the pan to swirl the batter in a thin coating across the pan surface.
On a griddle use a palette knife, this make take a little practice.
Cook for about two minutes then flip over. Cook for a further minute until crisp and golden brown, transfer to a warm plate and serve.