- Preheat the oven to 220°C. Brush the beef fillet with olive oil and season generously with sea salt and freshly ground black pepper. Using a large ovenproof frying pan on a high heat, first seal the beef and then transfer to the oven for 15-20 minutes for medium-rare (remember it will be cooked again in the pastry). When the beef is cooked to your liking, remove it from the oven, cover with Alfoil and place in the fridge to cool. In a food processor add mushrooms, onion and garlic. Pulse till finely chopped then transfer the duxelles (mushroom mix) to the frying pan you sealed the beef in with a splash of olive oil, add the thyme and fry for a 4-5 minutes until the mushroom mix has started to soften and darken.
- Add the brandy and cook to evaporate the alcohol and reduce the liquid, stirring all the time to make sure it doesn’t burn. The duxelle is ready when the mixture becomes quite thick (the consistency should be like a paste). Remove from the heat and season with salt and pepper and allow to cool.
- Take the fillet from the fridge and remove the foil. Overlap two pieces of cling film over a large chopping board lay 10 slices prosciutto on the cling film, slightly overlapping, in a double row. Spread half the mushroom duxelles over the center of prosciutto, then sit the fillet on top and spread the remaining duxelles over the meat. Use the cling film’s edges to draw the prosciutto around the fillet, then roll it into a firm sausage shape, twisting the ends of cling film to tighten it as you go. Place the covered fillet back in the fridge to chill while you roll out the pastry.
- Roll the pastry into a large square shape. Unwrap the chilled fillet and place in the centre. Brush a little of the beaten egg on the edges of the pastry and roll it so the edges are tucked underneath. Place the fillet on a medium oven tray lined with Multix bake. Lightly score the top to make a feather pattern with a sharp knife making sure you don’t cut through the pastry. Cover again with cling wrap and chill for at least 30 minutes before cooking.
Note: Chilling this dish before cooking it helps the pastry keep its shape. Preheat the oven to 200°C. Brush the Wellington all over with a little more beaten egg and cook until golden and crisp – about 20 -25 mins for medium-rare beef, 30 mins for medium. Allow to rest for about 10 mins before serving in thick slices. Serve with steamed green vegetables or a green salad.
Hot Tip: Chilling pastry before you cook it helps it keep its shape if you cover it with Multix Cling as it chills the pastry stays moist and tender.