To make the pancakes - sieve the flour into a bowl, add the egg, salt and pepper, herbs and milk. Stir thoroughly to form a smooth batter and mix in the melted butter. Add a little of the mixture to a pan, with some butter and cook for a few seconds until lightly browned on both sides. Turn onto a plate, wipe the pan clean and continue to make pancakes until all the mixture is gone.
Trim the meat and season with salt and pepper. Melt the butter and vegetable oil in a large frying pan and add the seasoned meat – seal over a high heat on all sides. Cook for 2 – 3 minutes and remove meat from pan. Cook the sliced mushrooms in the same butter and blend with the pate. Spread the pate mix over the pancakes and keep refrigerated.
Roll out pastry on a lightly floured surface approx ¼ inch thick into a rectangle large enough and long enough to encase the beef, leave to rest for 15 mins in refrigerator, then egg wash the pastry sides. Place the pancakes on the centre of the pastry, pate side up. Place the meat on top and cover in the pancake and pate, ensuring all sides are covered. Roll the pastry around the meat and pancake ensuring the joins are well sealed. Decorate the top of the pastry and place onto a baking sheet
Place into a pre heated oven at 220c 425f gas mark 7and cook for approx 30 – 35 minutes for medium/rare, and 40 – 45 minutes for medium/well done.