Let tenderloin reach room temperature.Place the tenderloin in a large pan with oil and heat on medium-high heat.
Season it with salt, pepper, and thyme.Now The beef should be seared on all sides, but not cooked through.
Spread Dijon mustard on the beef while it is still hot. Let it cool off.
Chop the shallots, garlic, and mushrooms.
Heat a nonstick cold pan on medium heat. Cook the chopped vegetables. Season with salt. Let it cool down and cook until it forms a paste. This is your Duxel paste.
Place a sheet of cellophane on your table and then spread the Duxel.Place your tenderloin on the Duxel, then roll the cellophane around the edges.
Now This should be kept in the refrigerator for between 30 minutes and 1 hour.Preheat the oven to 220 degrees Celcius
Dust flour on your table. Next, place the pastry block on your table and roll it into a large square measuring approximately 1/3 cm. Place the beef on the bottom of the pastry