Vol au Vents

Name: Vol au Vents
Yield: Makes 4
Ingredients: 375 ml (13 fl oz/1½ cups) milk; 2 tablespoons plain (all-purpose) flour; 2 spring onions (scallions), finely chopped; 40 g (1½ oz) butter; 1 egg, lightly beaten; 250 g (9 oz) block ready-made puff pastry, thawed