Serves 6, prep time 20 minutes, cooking time 45-50 minutes
400g mushrooms, finely chopped
2 tbsp olive oil
750g prime beef fillet
2tbsp of English mustard
Course black pepper
8 slices of Parma ham
2 sheets of cling film
2 tbsp of flour to dust
1 sheet of ready-made puff pastry
2 free-range eggs, beaten
1 tbsp of black sesame seeds
Preheat the oven to 200 degrees. Place the mushrooms in a food processor and blitz until finely chopped. Heat a pan over a high heat, add the mushrooms, cook for about 10 mins, stirring frequently. Cook until all the moisture has evaporated. Then spread out the mushrooms on a plate and allow to cool.
Add some oil to the pan on a medium heat. Season the beef and sear in the hot pan for 30 seconds on all sides. Remove the meat from the pan, allow to cool, then brush English mustard.
Lay a sheet of cling film on a work surface and arrange the Parma ham slices into a square slightly overlapping. Spread the mushrooms over the ham, then place the seared beef in the middle.
Keeping a tight hold of the cling film, roll the Parma ham and mushrooms around the beef. Twist and secure the ends of the cling film. Chill in the fridge for 20 mins to allow the beef to set.
Dust a flat surface with flour, roll out the puff pastry. Remove the cling film from the beef, then lay in the centre of the pastry sheet. Brush the edges with egg yolk. Fold the ends over, then wrap the pastry around the beef. Turn over, so the join is underneath, and place on a baking sheet.
Score the pastry diagonally with a shape knife, brush with egg, top with sesame seeds and rock salt. Chill in the fridge for about 15 mins. Place in the oven for 30 minutes, lower the heat to 180C and cook for another 15-25 mins. (Cook for longer, if you want the beef to be medium, rare). Remove from the oven and rest for 10-15 mins before slicing and serving.