Method
1
Finely chop the mushrooms and shallot.
2
Heat the butter and olive oil in a skillet over medium heat.
3
Add the mushrooms, shallot, thyme, and a pinch of salt.
4
Cook the mushroom mixture until dry, about 10 minutes.
5
Spread the mushroom mixture on a plate to cool completely.
6
Season the beef pieces with salt and pepper.
7
Heat a thin layer of oil in a skillet over high heat.
8
Sear the beef pieces briefly on all sides.
9
Transfer the beef to a plate to cool.
10
Brush the cooled beef pieces with Dijon mustard.
11
Lay one prosciutto slice on a clean work surface.
12
Spread a thin layer of cooled mushroom mixture over the prosciutto.
13
Wrap one piece of beef in the prosciutto and mushroom mixture.
14
Repeat with the remaining beef, prosciutto, and mushroom mixture.
15
Refrigerate the wrapped beef for 10 minutes.
16
Heat the oven to 200°C and line a baking sheet with parchment paper.
17
Cut the puff pastry into 12 squares large enough to enclose the beef pieces.
18
Place one wrapped beef piece in the center of each pastry square.
19
Fold the pastry around each piece and seal the edges underneath.
20
Cut small stars from the pastry scraps.
21
Place a pastry star on each Wellington.
22
Whisk the egg with the tablespoon of water.
23
Brush the pastry with the egg wash.
24
Bake the Wellingtons until the pastry is golden and the beef reaches 60°C at the center, about 18 to 22 minutes.
25
Rest the Wellingtons for 5 minutes.
26
Combine the cranberries, sugar, water, and orange juice in a small saucepan.
27
Simmer the cranberry mixture until the berries burst and the sauce thickens, about 8 to 10 minutes.
28
Cool the cranberry sauce slightly.
29
Serve the Wellingtons with cranberry sauce and rosemary sprigs.