A good French pancake should be too thin to toss with ease. When I was at cookery school, our teacher used to say that if we could toss it we should toss it out!
Put all the ingredients except the fat for frying in a liquidizer or food processor and whizz briefly. (In the absence of a machine, sift the flour with the salt into a bowl and make a well in the centre, exposing the bottom of the bowl. Put the egg and egg yolk, along with a little of the milk, into this well. Using a fork or whisk, mix the egg and milk together, at fir