Beef Tenderloin with Robuchon Potatoes
Beef tenderloin itself is an indulgence. Pair it with Joel Robuchon’s recipe for pommes puree and you have a truly special meal, not to mention the need for a few extra trips to the gym! Robuchon’s famous recipe calls for Ratte potatoes, which is a small fingerling size potato with a buttery texture. Yukon gold potatoes make a fine substitute. The recipe is essentially just potatoes, butter and milk, but cooked with a deliberate technique to create a light velvety texture.
I rarely cook beef tenderloin, but when I do, I prefer to cook the meat in a water bath. Because beef tenderloin has so little fat compared to other cuts of beef, it has two weaknesses. First, it’s a little flavorless. Second, it’s easy to overcook. This method allows you to cook the meat evenly without concern of overcooking or drying the outer surface. Once cooked sous vide, the meat is ready for any variety of final preparation to add flavor, in this case pan seared with butter, thyme and shallots. The clarified butter is important to the searing step, as it has a higher smoke point and won’t burn.
For the potatoes
1 pound potatoes, scrubbed but not peeled
½ pound chilled butter, cut in small pieces
½ to ¾ cup warm whole milk
Salt to taste
For the beef tenderloin
1 Chateaubriand cut beef tenderloin
Salt and pepper
3 tablespoons clarified butter
3 or 4 springs of thyme
1 shallot, peeled and cut in half
2/3 cup Beef Demi-Glace
Vegetables for garnish
Coarse sea salt
1. For the potatoes: Add the potatoes to a large pot, cover with cold water, and add 2 tablespoons salt. Bring to a boil and simmer about 20 minutes, or until a knife can be easily inserted and removed.
2. Remove from the heat and drain. Once cool enough to handle, peel the potatoes and pass them through a potato ricer (smallest grid) into a large saucepan.
3. Heat the pan over low heat, stirring the potatoes gently to drive off moisture. Gradually add the butter, stirring well after each addition to fully incorporate the butter.
4. Add the milk in a similar fashion, a little at a time and stirring continuously. You want a light, pudding like texture. With a wooden spoon or whisk, whip the potatoes to incorporate some air. Season with salt to taste.
5. Remove from heat and press the potatoes through a fine meshed tamis. Repeat and serve, or keep warm in a double boiler.
6. For the Beef Tenderloin: Prepare a water bath set to 130F. Trim the beef of any fat or silver skin. Season with salt and pepper, and seal in a vacuum bag. Cook the meat sous wide for 1 hour.
7. Remove the meat from the bag and pat dry. Heat a large heavy bottomed skillet over high heat. Add the butter, thyme and shallots.
8. Sear the tenderloin on all sides in the pan, tipping the pan and continuously basting the meat with the butter.
9. Remove and rest before serving. Add the demi-glace to the pan and warm through.
10. To serve, slice the meat into 1 inch thick servings. Spoon demi-glace onto a plate in a small circle. Spoon potatoes carefully into the middle of the sauce, so that the sauce runs to the outside of the potatoes. Place a slice of meat onto the potatoes. Garnish with coarse sea salt, roasted vegetables, and serve.