350-400g вeef fillet; 1 sheet of flaky pastry; 2 tbsp olive oil; 8-10 medium sized mushrooms; 1 egg; salt; black pepper
Defrost the pastry. Peel the mushrooms with a brush or dry cloth, quarter them and blend them in a blender for a few seconds. Fry them in a hot dry frying pan until all the liquid has been absorbed, season with salt and set aside. Clean and trim the beef fillet, rub it with salt, pepper and oil. Seal the beef on all sides in a dry frying pan on a high heat and set aside. Roll the pastry to a thickness of 5mm and so that it is slightly longer than and three times wider than the fillet. Spread the mushroom mixture evenly over the pastry and then place the fillet on top. Baste the edges with beaten egg and wrap the meat in the pastry, trimming off any extra pastry. Place the wellingtons seam down on a sheet of greaseproof paper. Cut several strips from the remaining pastry and stick them on in a lattice pattern with the beaten egg. Brush the wellington with a mixture of egg yolk and 1 tbsp water and leave it to stand for 15 minutes. Bake in an oven at 150ºC for 20 minutes and at 150ºC for another 10 minutes. Remove from the oven and cover with a cloth. Leave to stand for 10-15 minutes before slicing into 1-2cm thick slices and serving.