Heat oven to 220°C in fan mode or 4D Hot Air programme on the Bosch Combi-steam oven.
Place beef on a wire grill with the roasting tray below, brush the meat with butter and season with fresh, crushed pepper and salt.
Pan sear the beef in vegetable oil and butter until all the sides are seared.
Roast the beef in the oven for about 15 minutes. Cooking time varies for different meat sizes.
* Chef’s tip: To achieve medium doneness, thrust a cooking thermometer into the beef and cook till the internal temperature reaches 60°C.
When the beef is cooked to your liking, remove from the oven to cool, then chill in the fridge for about 20 minutes.
While the beef is cooling, pulse chestnuts and mushrooms in a food processor so they don’t become a slurry.
Heat cooking oil in a large pan and fry chestnuts and mushrooms on medium heat. Add in thyme and fry for about 10 minutes, stirring regularly until the mixture is softened.
Season the mushroom mixture with salt and white pepper, pour over the wine and cook for about 10 minutes until all the wine has been absorbed.
The mixture should hold its shape when stirred. Remove the mixture from the pan to cool and discard the thyme.
Overlap two pieces of cling film over a large chopping board. Lay bacon on the cling film, slightly overlapping, in a double row.
Spread half the chestnut and mushroom mixture over the bacon, place the fillet on it and spread the remaining mixture over the fillet.
Use the cling film’s edges to draw the bacon around the fillet, roll it into a sausage shape and twist the ends of the cling film to tighten it.
Chill the meat in the fridge while preparing the pastry. Take out the pastry sheets with the plastic on the base on the table.
Remove the meat from the cling film and lay it in the centre of the pastry. Brush the pastry’s edges with egg wash to seal it, then wrap the meat. Thereafter, place it in chiller for 15 minutes.
Line tray with baking paper and heat oven to 200°C. Brush the Wellington with a little more egg yolk and cook until golden and crisp—for about 30-40 minutes. Cooking time varies for different meat sizes.
Allow the meat to stand for 10 minutes before serving in thick slices.