This is one of the most ingenious ideas I have seen out there for Valentine's Day. It is elegant, simple to prepare and can be made ahead up to a point. Just before you sit down, slice the beef, warm up the mushrooms and arrange everything on the tart. Frankly, I don't even think it needs the mousse. Instead, I would add some madeira or cognac to the drippings from the filet, reduce and add that to the mushrooms instead of the white wine. Accompany with fresh asparagus or green beans and you are set to go.
8 ounces beef tenderloin
Coarse salt and freshly ground pepper
4 teaspoons olive oil
All-purpose flour, for dusting
1 sheet (11-inch square) thawed frozen puff pastry, preferably DuFour
1 tablespoon unsalted butter
8 ounces cremini mushrooms, thinly sliced
2 teaspoons fresh thyme leaves, plus more for garnish
1 garlic clove, minced
1/2 cup dry white wine
2 ounces foie gras mousse (about 1/4 cup)
1.Preheat oven to 400 degrees. Season beef with salt and pepper. Heat 2 teaspoons oil in an ovenproof skillet over medium-high heat. Add beef, and cook until completely browned, about 1 minute per side. Transfer skillet to oven, and cook to desired doneness (130 degrees for medium-rare, 8 to 9 minutes). Transfer beef to a plate, and let rest, uncovered, for 10 minutes.
2.Meanwhile, on a lightly floured surface, cut two 5 1/2-inch squares from puff pastry; reserve remaining dough for another use. Using a paring knife, score a 1/2-inch border around each square. Place on a parchment-lined baking sheet, and refrigerate for 15 minutes.
3.Bake for 10 minutes. Reduce oven temperature to 375 degrees, and continue to bake until puffed and golden brown, about 10 minutes more.
4.Meanwhile, melt butter with remaining 2 teaspoons oil in a clean skillet over medium-high heat. Add mushrooms, thyme, and garlic, and cook until mushrooms are tender and garlic has softened, about 8 minutes. Add wine, and cook until reduced by half, about 1 minute. Using a slotted spoon, transfer mixture to a small bowl. Cover with tin foil if not using immediately.
5.Add foie gras mousse to skillet, and reduce heat to low. Stir until just melted. Remove from heat.
6.Using the back of a spoon, flatten inside portion of each pastry square. Thinly slice beef, and arrange slices on top of pastry. Top with mushroom mixture, and drizzle with sauce. Serve immediately.
From Martha Stewart Living, February 2008