1. There is a recipe for basic roasted filet of beef served in her "Parties!" book, as follows:
1 whole filet of beef (4 to 5 lbs) trimmed
2 tbsp unsalted butter at room temperature
1 tbsp kosher salt
1 tbsp coarsely ground pepper
Preheat oven to 500°. Pat the filet dry with paper towels and place on a baking sheet. Spread the butter with your hands all over the filet. Sprinkle with salt and pepper. Roast for 22 minutes for rare or 25 for medium-rare.
Remove beef from the oven and cover tightly with foil. Let meat rest for 20 minutes. Remove string and slice thickly.
The sauce recipe she includes is for gorgonzola sauce, but she says that you can use mustard and horseradish (no substitution quantities specified) to flavor the sauce instead. Written as follows:
4 cups heavy cream
3 to 4 ounces crumbly gorgonzola
3 tbsp grated parmesan
3/4 tsp kosher salt
3/4 tsp pepper
3 tbsp minced parsley
Bring the heavy cream to a full boil in a medium saucepan over medium-high heat, then continue to boil rapidly for 45 to 50 minutes, until it's thickened, like a white sauce, stirring occasionally.
Remove pan from heat and add the gorgonzola, parmesan, salt, pepper and parsley. Whisk rapidly until cheeses melt, then serve.