Classic beef wellington

Method

1. Heat a large nonstick frying pan over a medium-high heat, then sear the beef all over. Wrap tightly in a double layer of cling film to shape into a cylinder, then chill for 30 minutes (see tips).
2. Heat the oil and butter in the pan, then add the mushrooms. Fry over a medium heat for 5 minutes until soft and starting to colour, then add the thyme, garlic, vinegar and wine.  Bubble for 5-10 minutes until the liquid has mostly evaporated. Take off the heat, stir in the crème fraîche, mustard and seasoning. Cool.
3. Heat the oven to 200°C/180°C fan/ gas 6. Overlap 6-7 parma ham slices on a chopping board to make a rectangle longer than the beef fillet. Spread half the mushroom filling over the ham. Put the fillet on top, then cover the fillet ends with 2 more ham slices. Wrap the parma ham around the fillet – it will stick to it – then spread the rest of the filling over the top half. Layer the rest of the parma ham evenly over the mushroom-coated beef so it’s fully, neatly encased. Season, wrap in cling film, then chill.
4. Unroll a pastry sheet and cut into a rectangle 2-3cm longer and wider than the beef fillet (reserve the trimmings). Prick all over with a fork, put on a baking paper-lined baking sheet and cover with another baking sheet to stop it puffing up. Bake for 15-20 minutes until golden and crisp, then remove the top sheet.
5. Remove the cling film from the beef and put in the centre of the cooked pastry. Drape the other pastry sheet over the beef, pressing to remove as much air as possible (fold it at the ends as though wrapping a box). Crimp the edges with your fingers to seal with the cooked pastry, then trim around with a sharp knife. Brush all over with egg.
6. Lightly score a diamond pattern in the pastry using a sharp knife, then cut out stars with the pastry trimmings, brush with egg yolk and attach. Brush all over with egg yolk again, then chill for 30 minutes (or freeze for 20 minutes).
7. Brush with egg yolk a third time, then bake for 30-35 minutes until golden and puffed, and a digital probe thermometer pushed into the centre reads 55-60°C (for medium rare – for medium, cook for 35-40 minutes). Rest for 5 minutes, then slice and serve.