Like ice cream, the FDA says frozen custard must contain 10% milk fat, but it also has to be made with at least 1.4% egg yolk. Some ice creams also contain eggs, but it's not a requirement.
Brush the edge of the pastry with a little milk and then pile the apples into ... and arrange on warmed serving plates with some of the custard. Pour the remaining custard into a jug and hand ...