Courgette sauce with basil and beaten egg yolk, from Marcella Hazan’s The Essentials of Classic Italian Cooking.
An old favourite this. The flavour of the courgette is right at the front, as although it tastes creamy, it hasn’t got any cream in it.
The trick is to ensure the flour and milk binding doesn’t split in the butter, which means it really is a matter of turning the heat right down under the butter and pouring it in bit by bit and stirring constantly.
