Splash of olive oil
2-pound piece beef tenderloin, taken from the center, with an even thickness of about 4 inches
9 ounces crimini mushrooms, very finely chopped
1 large garlic clove, finely chopped
1 tablespoon Madeira
1 sheet puff pastry, defrosted
All-purpose flour, for dusting
6 slices prosciutto
1/2 teaspoon mustard powder
1 egg, beaten, for brushing
Madeira Sauce (see recipe)
Buttered new potatoes
Green beans or a green salad
1. Season the beef all over with black pepper. In a very hot heavy-bottom skillet, heat the oil until smoking. Add the beef and quickly brown it all over, about 5 to 10 seconds on each side, not forgetting the ends. Remove to a board and let cool completely.
2. Add the mushrooms to the pan and saute over medium heat for about 5 minutes, letting them brown, but stirring occasionally. Add the garlic, stir for a minute, then add the Madeira and some salt and pepper and cook until all the liquid has evaporated. Remove to a bowl and let cool.
3. Roll the pastry out on a floured counter until about 1/8 inch thick. Cut to fit your piece of beef so it is large enough to wrap it with a generous overlap. Lay 4 prosciutto slices side by side on the pastry so they are touching, then spoon most of the mushroom mix over the ham and pat down. Sprinkle the beef with the mustard powder and rub all over, then place the fillet on top of the mushrooms in the center of the pastry. Spoon over the remaining mushroom mix, pat down, and lay the two final slices of prosciutto lengthwise along the beef. Carefully and tightly bring the lower slices of prosciutto up and over the beef to wrap it. Then trim the pastry, brush all the pastry edges with beaten egg, and fold up to enclose the beef in the most dainty but efficient way you can. Place on a baking sheet lined with wax paper, with the pastry folds on the underside, and brush all over with beaten egg.
4. Freeze the beef on the lined baking sheet. When frozen, carefully transfer into a bag and freeze until required. Let stand for about 24 hours in the fridge before cooking. When ready to cook the beef, preheat the oven to 425°F. Remove the beef from the fridge and place on a baking sheet. Leave for 20 minutes at room temperature, then bake in the oven for 30 to 35 minutes, or until the pastry is golden brown. Let rest for 5 to 10 minutes before slicing thickly and serving with Madeira sauce.
Per serving (based on 6, without side dishes and sauce; see sauce recipe for additional data): 824 calories, 54 grams protein, 41 grams carbohydrates, 1 gram sugar, 48 grams fat, 161 milligrams cholesterol, 494 milligrams sodium, 2 grams dietary fiber.