Beef Wellington

Ingredients:

Puff pastry

• 1 sheet frozen puff pastry, thawed
• 1 large egg

Beef

• 2 tablespoons unsalted butter
• 2 tbsp. l. olive oil
• 1.3 kg ground beef with 20% fat content

Mushrooms

• 4 tablespoons unsalted butter
• 1/4 cup olive oil
• 900 g of champignons, thinly sliced
• 6 cloves garlic, crushed
• 2 bunches fresh thyme, leaves picked and chopped
• 1 large red onion, finely chopped

Sauce

• 2 tablespoons unsalted butter
• 2 tbsp. flour
• 1/4 cup grainy Dijon mustard
• 3 cups beef broth
• 0.5 cup chopped fresh parsley
• Special equipment: ring with a diameter of 10 cm.

Preparation:

1. Puff pastries:
   
   Preheat oven to 200°C (400°F). Line a baking sheet with parchment paper. Using a 10cm (4 in) diameter ring, cut out 4 circles of puff pastry. In a small bowl, beat an egg with a little water. Brush the top of each circle with the beaten egg and place on a parchment-lined baking sheet. Bake until the circles are puffed and the tops are light golden, about 15 minutes. Remove and set aside. Reduce oven temperature to 190°C (350°F).
2. Beef:
   
   In a large skillet over medium heat, melt the butter. Add the onion and ground beef, breaking it up into small clumps. Season with 1 teaspoon of salt and a few turns of black pepper and cook, stirring, until the meat is browned, about 5 minutes. Using a slotted spoon, transfer the beef to a 9x13 inch baking dish. Pour the fat from the skillet into a bowl and set aside.
3. Mushrooms:
   
   In the same skillet, melt the butter over medium heat. Add the mushrooms and cook until they release their liquid, wilt, and darken, 8-10 minutes. Add the garlic, thyme, and onion, season with salt and pepper to taste. Cook until fragrant, about 4 minutes more. Arrange the mushrooms in a baking dish on top of the beef.
4. Sauce:
   
   Combine butter and flour in a microwave-safe bowl and microwave on high for 1.5 minutes.
5. In a skillet over medium heat, heat the mustard, flour-butter mixture, and beef fat and stir. Add the broth, plenty of black pepper, and a pinch of salt. Bring to a boil; simmer until the sauce thickens, 5-8 minutes. Remove from heat and stir in the parsley.
6. Pour the sauce over the mushrooms and beef. Arrange the puff pastry on top. Bake, uncovered, until heated through and the sauce is bubbling, 15-20 minutes.