Beef Wellington (Granny's)

There's no doubt that Beef Wellington is delicious. How can it not be? The exterior is a light, crisp, buttery crust, glazed a deep, shiny golden brown, twinkling with crystals of sea salt.

1 (2 lb) beef tenderloin (1 kg)
1 lb puff pastry dough, thawed
½ cup mushrooms, finely chopped
¼ cup shallots, finely chopped
2 cloves garlic, minced
1 Tbsp. extra-virgin olive oil
1 Tbsp. unsalted butter
1 Tbsp. Dijon mustard
2 Tbsp. fresh thyme, chopped
2 Tbsp. fresh parsley, chopped
1 egg, beaten
kosher or sea salt
black pepper, freshly ground

Preheat the oven to 425°F (220°C/200°C fan, Gas Mark 7).

Season the beef tenderloin with salt and pepper.

In a large skillet, heat the olive oil and butter over medium heat. Add the mushrooms, shallots and garlic and cook until the mushrooms have released their liquid and are tender.

Remove the skillet from the heat and stir in the Dijon mustard, thyme and parsley.

Roll out the puff pastry dough on a lightly floured surface into a large rectangle.

Place the cooked mushroom mixture on top of the puff pastry, leaving a border of about 1" all the way around.

Place the beef tenderloin on top of the mushroom mixture. Roll up the puff pastry around the beef tenderloin, tucking the edges underneath and sealing the seams with beaten egg.

Transfer the beef Wellington to a baking sheet lined with parchment paper. Brush the top with beaten egg.

Bake for 35-40 minutes or until the puff pastry is golden brown and the beef is cooked to your desired doneness.

Allow the beef Wellington to rest for a 10 minutes before slicing and serving.