Pancake Batter: Beat together milk and eggs, then gradually whisk in flour. Add 1 pinch of salt and sugar. The batter should be thin.
Heat butter in an 18cm pan. Pour small portions of batter into the pan to create 12 small pancakes. When bubbles appear, flip pancakes over and cook until brown on both sides. Keep warm in an oven set very low.
Caramelised Apples: Heat 50g butter on medium high heat in a large frying pan. Fry apples until they are light brown. Sprinkle with sugar and saute until the sugar has caramelised. Pour in apple juice, stir, then remove apples from the liquid.
Fill pancakes with apples and roll up.
Sauce: Beat remaining 20g butter into the apple juice in the pan.
To Serve: Arrange three pancakes per serving on a plate and dust with icing sugar. Serve with the sauce and garnish with mint leaves, if you like.