This is a delicately smooth apple and lemon tart topped with thin slices of sharp lemon frosted with egg white, which look just like drawings of snowflakes, hence the name. The pastry is particularly good and very easy to achieve, crisp and biscuit-like. It is best served cold (but not taken straight from the fridge).
Make the pastry first. Sift the flour and salt and caster sugar into a bowl. Stir in the semolina. In a small saucepan, melt the butter with the water. Add the hot liquid all at once to the flour. Stir around with a wooden spoon to form a dough. Press this warm dough evenly all over the bottom and sides of a