About the Fillet of Beef in Pastry

Regarding the fillet of beef in pastry with wild mushrooms and red wine sauce from the newer Christmas book, please can you tell me if the timings for cooking are from chilled in the fridge or should it be brought back to room temperature before cooking? i'm a bit nervous as its hard to tell if the beef is cooked as it's covered in pastry. Any tips gratefully received. Thanks