Step 1

Thoroughly season the beef with salt and pepper. Cover the top, bottom, and both sides.

Step 2

In a skillet on medium-high heat, sear the meat on all sides. Do not cook thoroughly, as the meat will finish cooking in the oven. After searing, remove the meat from the pan and place it in the fridge, allowing it to cool.

Step 3

While the meat is cooling, cook the mushroom and onion mixture in the same pan, utilizing the leftover flavor from the meat. Cook the mixture on medium heat for 1 hour, until all of the moisture is removed.

Step 4

Preheat the oven to 425 F. Prepare a baking sheet with parchment paper. Utilize one sheet of puff pastry, slightly rolled out and place it on the baking sheet. If you have a larger piece of meat, you may need both sheets.

Step 5

Spread the mushroom and onion mixture onto the puff pastry with a spatula, leaving room on the edges.

Step 6

Place the prepared meat in the middle of the prepared puff pastry. Wrap the puff pastry around the meat.

Step 7

Mix the egg with 1 teaspoon of water. Brush the egg wash on the prepared loaf, then score the top with a knife. Place the beef wellington in the oven and cook for 45 minutes.

Step 8

Once cooked, remove the beef wellington from the oven. Garnish with sprigs of thyme and salt, if desired.