Dip a piece of kitchen paper in vegetable oil and grease a small frying pan. Ladle a spoonful of batter into the pan. With a flick of the wrist swivel the pan in order to get a nice even covering all over. A good crepe should be paper- thin. Cook on a high heat and flip it over when you see the edge turning golden brown. Remove crepes from pan and keep aside in a warm place.
Combine the lemon with the orange juice and pour it in when the caramel is bubbling. Be careful not to burn the butter or yourself. Add Grand Marnier and continue whisking as the mixture curdles a little and let it cook for 10 minutes to reduce. Finally mix with an electric hand-mixer to ensure that the butter is fully integrated.
Fold the crepes in 4 and put them into a deep frying pan. Spoon in enough orange butter to barely cover them and, on a high heat, reduce the liquid, turning the crepes over to make sure that they absorb the orange butter.
To serve, place the crepes on a dessert plate. Spoon the orange butter over them and garnish with a sprinkling of the zest.