I've cooked a Wellington a couple of times and whilst I've been pleased with the overall outcome on each occasion the pastry comes away when serving. This is purely for aesthetic reasons.
I use a 1kg fillet, seared, then rolled in to a sausage on a bed of prosciutto ham and a mushroom duxelle with some chicken liver pate mixed in.
I chill this before wrapping in egg washed puff pastry and cooking for about 40 minutes. This has resulted in rare beef, a good crisp pastry that holds its form until cutting it for serving.
It wasn't too wet - it just seems the pastry doesn't want to affix itself to the contents.
Any ideas on how to improve this?
I adapted my recipe from this one http://www.bbcgoodfood.com/recipes/2538/beef-wellington