Beef Tenderloin stuffed with creamed winter greens

A simple yet elegant holiday roast recipe. This recipe was written for my friends at Smithey Ironware using their beautiful oval roasting pan, one of my favorite carbon steel pieces. A center-cut beef tenderloin is butterflied, then topped with rich and creamy sautéed greens, rolled, tied, and roasted. You can butterfly the meat yourself with a sharp knife, or ask the butcher to do it for you. The creamed greens can be made up to 2 days in advance.

Beef Tenderloin Stuffed with Creamed Winter Greens
Serves 6

Creamed Winter Greens 

8 ounces dark leafy greens, such as spinach, mustard greens, collards, and kale (tough stems removed)
2 tablespoons unsalted butter 
2 tablespoons finely chopped shallot
2 teaspoons finely chopped garlic
pinch red pepper flakes
3 tablespoons all-purpose flour
3/4 cup heavy cream
2 tablespoons freshly grated parmesan or asiago cheese
Coarse kosher salt and freshly ground black pepper, to taste  

For the Tenderloin

2 1/2 to 3-pound center-cut beef tenderloin, butterflied 1/2 inch thick (have your butcher do this)
Coarse kosher salt and freshly ground black pepper
2 tablespoons olive oil

Horseradish Cream Sauce

1/2 cup sour cream
3 tablespoons prepared horseradish
1 tablespoon heavy cream
1 tablespoon lemon juice
1/4 teaspoon kosher salt
Freshly ground black pepper, to taste

Prepare the filling: 

1. Bring a large pot of water to a boil and season with salt. Add greens and cook just until color is set, about 1 minute. Transfer to a large bowl of ice water. Once cool, drain the greens. Use paper towels or a clean kitchen towel to squeeze out all excess moisture, then finely chop. You should have about 1 1/2 cups (5 ounces) prepared greens.

2. In a medium saucepan, melt the butter. Add the shallot, garlic, and red pepper flakes and cook over medium-low heat, stirring occasionally, until softened, about 2 minutes. Add the flour and cook, stirring, until the flour is golden, about 2 minutes. Whisk in the cream until smooth, then stir in the prepared greens. Cook 1-2 minutes longer, until mixture thickens and most of the moisture has evaporated. 

3. Remove from heat and stir in the cheese, then season with salt and pepper to taste. Let cool to room temperature (or, cover and refrigerate up to 1 day ahead). 

Make the sauce:

1.  In a small bowl, whisk together horseradish cream sauce ingredients. Refrigerate at least 1 hour or up to 3 days. 

Stuff and Roast the Meat: 

1. Preheat the oven to 400°F. 

2. Lay a piece of plastic wrap over the inside of the butterflied tenderloin, then gently pound the meat until it is an even 1/2-inch thickness. 

3. Season the interior with salt and pepper, then spread the cooled creamed greens evenly over the meat, leaving a 1/2-inch border around the edges. Roll up the filet lengthwise and tie with kitchen twine at 1-inch intervals. Season the exterior with salt and pepper.

4. Heat olive oil in a large skillet or oval roasting pan over medium heat until it shimmers. Add prepared roast and sear until deeply browned on all sides, about 8-10 minutes total. Turn the roast seam-side-down, then transfer the whole pan to the preheated oven and roast until a meat thermometer inserted into the center reaches 120˚F, about 20 minutes for medium-rare. Transfer beef to a cutting board and let rest for 6-8 minutes, then slice thick and serve with chilled horseradish cream sauce.