Chateaubriand in a Brioche Crust

By danaheller

Ingredients

• Mushroom Duxelle:
• 1 3/4 to 2 lbs trimmed tenderloin of beef, cut from the top end to the middle
• 1/4 cup clarified butter
• 12 good spinach leaves
• 3 tbs butter
• 14 oz button mushrooms, wiped and finely chopped
• juice of 1 lemon
• 1/2 cup finely chopped shallots
• 4 tbs heavy cream
• To Assemble:
• 14 oz brioche dough (about 1/2 recipe)
• flour for dusting
• 3 herb crepes, 11-12 inches in diameter
• 1 egg yolk beaten with 1 tsp milg (egg wash)
• salt and freshly ground pepper

Details

Servings 4

Preparation

Step 1

First make the mushroom duxelle. Heat the butter in a frying pan over medium heat. Add the mushrooms and lemon juice and cook for a few minutes, until all the liquid has evaporated. Add the shallots and cook until softened, then add the cream and cook, stirring continuously, until it is all absorbed. Season to taste, transfer to a bowl, and let it cool, then refrigerate.
To pre-cook the beef, preheat the oven to 400 degrees. Heat the clarified butter in a roasting pan. Season the beef with salt and pepper, put it in the roasting pan, and sear over a medium heat for 3 to 5 minutes, until golden brown all over. Put the pan in the oven and roast the beef for 7 minutes, turning it over halfway through. At this stage, the beef will be very rare. Take it out of the oven, place on a rack and let cool.
Briefly blanch the spinach leaves, refresh them, and spread out to drain on a dish towel.
To assemble, roll out the brioche dough on a lightly floured surface to a rectangle, roughly 10x14 inches and 1/8 inch thick. Lay 2 crepes slightly overlapping along the middle, letting them overhang the ends by about 2 inches. Cover with a few spinach leaves. Using a spoon, spread a 1/2 inch band of mushroom duxelle down the middle of the crepes. Put the cold fillet of beef on top and cover the whole surface, including the ends, with the remaining duxelle. Drape the rest of the spinach over the duxelle, then fold the crepes up over the beef, and cover it with the unused crepe (halved if necessary). The beef should now be snugly wrapped.
Lightly brush the short ends of the brioche with egg wash. Fold one long side over the beef, brush with egg wash, then fold the other long side over the top. Roll out the brioche ends and trim to make 3-inch flaps. Brush lightly with egg wash and them up over the fillet. Hold a baking sheet at a 45 degree angle against the side of the brioche-wrapped beef, then tilt and invert the parcel onto the baking sheet with the seam underneath, refrigerate for 30 minutes.