Photo by Babiche Martens
- Melt half the butter in a heavy-based frying pan until hot. Sear the fillet all over and set aside until completely cold.
- Place the onion, garlic, mushrooms and thyme into a food processor and pulse until completely chopped.
- Add the rest of the butter to the frying pan then the onion mixture.
- Cook until reduced, then add the wine and continue cooking until all evaporated. Remove and let cool.
- Lay the prosciutto on to a large piece of plastic wrap, overlapping the sides.
- Spread the mushroom mix down the middle, place the beef on top of the mushrooms.
- Using the plastic wrap, roll the prosciutto around the beef and form a log. Twist the ends of cling film into a bonbon shape to seal. Refrigerate.
- One hour before cooking, remove the meat from the fridge. Unroll it from the clingfilm.
- Preheat the oven to 200C.
- On a lightly floured board, roll the puff pastry large enough to be able to wrap around the fillet and fold in the ends. Place meat in the middle, fold in the ends, then roll. Seal edges with a little water.
- Brush with a little egg. Place into the oven for 25 minutes, or until the pastry is puffed and lightly browned. A larger piece of meat may take 35 minutes. Serve hot with vegetables.