Feuilletés simply means puff paste in French. The English are the first to claim they grow the best asparagus so it is not surprising that it pops up on English menus, particularly in May and June when it is fresh off the fields. Once called ‘sparrow-grass’, but now affectionately known in the trade as simply ‘grass’.
There is really not much involved in the dish. If you can cut rectangles and trim asparagus, you are practically there. It is a little labour intensive which is why Mrs. Patmore would delegate it to a junior like Ivy.