Okay, I know how this is supposed to be done: Trim the tenderloin perfectly, remove all silver skin and such, then fold the tail under the middle so it's as even a cylinder as possible. Season, brush with melted butter, and lay on a sheet of brioche or puff pastry. Fold the pastry around the meat, trim, seal the edges well with egg yolk, brush the top with an egg yolk-milk wash, and bake about 35 minutes at about 450F. Now for reasons I don't want to get into here, having nothing to do with food, I don't want to do it quite this way. What I want to do is to cook the tenderloin sous vide in advance, to the perfect rare target temperature, then refrigerate. On the day, surround with pastry and bake long enough that the pastry is beautiful and the meat is hot but not any hotter than my target temperature was. So here are my questions: Is this a bad idea, and if so, why? Brioche or pate feuilletee? Time and temperature for the final bake? Many thanks in advance!