2 sticks unsalted butter, diced and chilled, plus extra for greasing
2 tbsp olive oil, for frying
1 large onion, peeled, finely chopped
2 cloves garlic, peeled, crushed
1 pint mushrooms, chopped
1 tablespoon parsley, chopped
(6) 6-ounce filet mignon steaks
(2) packages ready-to-roll puff pastry, thawed if frozen
plain flour, for dusting
1 large egg, beaten
3/4 cups red wine
black pepper
Preheat the oven to 375 degrees. For the filling, melt half the butter with half the oil in a frying-pan. Add the onion, garlic, and all the mushrooms and sauté for 10 minutes until tender and all the liquid has evaporated. Stir in the parsley. Place mixture in a bowl and season. Set aside to cool. Season the steaks. Wipe out the same frying-pan and heat until hot. Add the remaining oil and sear the seasoned steaks for 20-30 seconds on all sides. Set steaks aside to cool. Cut the pastry into 6 pieces, roll out on a lightly floured surface and brush with beaten egg. Divide the mushroom mixture between the squares and place a steak on top. Bring up two opposite corners of the pastry square to overlap the steak in the centre, seal and gently tuck in the sides, brush with a little beaten egg, and bring the remaining two corners up and seal. Place the parcels on a heated non-stick baking sheet, brush with beaten egg and bake in the oven for 25 minutes for medium-rare, or 5 minutes more for well done. Place the frying-pan that you used to cook the steaks back on the heat. Pour in the wine and allow to bubble down, then simmer until reduced by two-thirds. Just before serving, whisk in the remaining butter and season. Serve.
