I've seen quite a few videos where French chefs cook the puff pastry for mille feuille to the point where it's almost falling apart. It's completely browned throughout and the flaky layers are nearly indecriperal from each other. Appearantly this is done purposely and the hallmark of a good mille feuille by many French chefs. Claude Bosi is famous for always having one on his menu for example. By American standards the puff pastry is over-cooked, what's the rationale behind cooking it this way? Just a French preferance? I've never tasted puff pastry cooked that way but I can imagine it's texture and the maillard factor contribute to a different profile than I'm used to.