Sous Vide Fillet Mignon

Sous Vide Fillet Roast with Wild Mushroom Ragout
Photograph by A. Schloss

One of the cruel limitations of slow roasting is that ovens just won't go low enough. The numbers on dial thermostats stop at 200°F/100°C and most digitals won't sink below 170°F/75°C (a few graciously condescend to descend to 150°F/65°C). These temperatures are fine for roasting any tough cut of mammal, any bird, or vegetable, or fatty fish. But for delicate proteins, especially super expensive items, like beef tenderloin, wild king salmon, or foie gras a few excess degrees result in instant ruination, and that's too big a cost to bear.


Sous vide cookers allow you to regulate temperature to exact fractions of degrees, which means more than any other cooking method, sous vide yields perfect doneness on temperamental proteins.  With tough cuts that are always cooked above well-done this is not an issue, but for $27-a-pound fillet mignon exact control makes all the difference in the world. 

The most opulent recipe in Cooking Slow for Fillet Mignon in Wild Mushroom Ragout (page 186) is nearly effortless. Fillet steaks are browned at the highest heat possible, to make a beautiful crust without cooking the interior, and heated in the sous vide machine to whatever degree of doneness you prefer. I chose medium rare 130°F/54.4°C. While the steaks are cooking, an elegant wild mushroom sauce simmers, and when the two meet on a plate – pure opulence.

In sous vide (French for "under pressure") food is vacuum sealed in food-grade plastic and then submerged in a precisely heated water bath. To cook sous vide you will need two special pieces of equipment: a vacuum sealer (I use a FoodSaver) , and a sous vide machine to heat the water. There are two types: the sous vide supreme has the heating element and the water bath all in one. It is less expensive but not quite as accurate as a thermal circulator, which has more exact temperature control and a pump that circulates the water, ensuring consistent temperature throughout the water bath. Thermal circulators are sold separately from the water bath and fit neatly on any large pot, which makes them easy to transport and store. 

For this riff on sous vide fillet steaks in Cooking Slow I have switched the steaks to a whole fillet roast - way less to vacuum seal and a more elegant presentation. I raised the sous vide temp by 3°F because the roast needs a little more firmness to slice easily, and I devised two more toppings- a roasted tomato relish, and a palate altering composed butter that pairs roasted jalapenos with gorgonzola. Most excellent!

Fillet Mignon with Wild Mushroom Ragout + Two

Toppings (clockwise from 9 o'clock): Tomato Concasse, Jalapeno Gorgonzola Butter, Wild Mushroom Ragout
Photograph by A. Schloss

Makes 4 servings

Special equipment

Vacuum sealer and 2 food-grade plastic cooking pouches

Fillet Roast

1 1/2 lb/680 g  fillet mignon roast

1 tbsp Truffle Herb Chef Salt, or other truffle salt
2 tbsp/27g unsalted butter

Wild Mushroom Ragout

1/2 oz/15 g dried wild mushrooms, finely chopped, any type

3/4 cup/180 ml hot water
2 tbsp/27 g unsalted butter

2 shallots, finely chopped

8 oz/225 g mixed “wild” mushrooms, such as oyster, shiitake, cremini, porcini, morels, or chanterelles, coarsely chopped

1/2 cup/120 ml dry red wine

1/4 cup/60 ml tomato sauce

2 cups/480 ml good quality low-sodium beef broth

1 tbsp/2.5 g coarsely chopped fresh flat-leaf parsley

Slow Roasted Tomato Concasse

2 cups oven-dried tomatoes (see post)

12 basil leaves or 1 sprig rosemary, finely chopped

1 tsp aged balsamic vinegar

Jalapeno Gorgonzola Butter

2 jalapeno chilies, roasted (see post)

1 small garlic clove, minced

3 oz/85 g dolce Gorgonzola, without rind

2 tbsp/27 g unsalted butter, softened

2 tbsp extra-virgin olive oil

For the fillet roast: Season the roast with Chef Salt. Heat the butter in a large skillet, preferably cast iron, over high heat until the butter starts to brown.  Add the roast and brown on all sides. The pan should be hot enough to brown each side in less than a minute. The roast should remain as raw inside as possible.

Remove from the pan and turn off the heat. Put the browned beef into a large cooking pouch. Seal the bag to 90% vacuum (dry setting on a FoodSaver machine). Refrigerate until you are ready to sous vide the meat. If you are going to serve the roast with the mushroom ragout do not clean the skillet yet.

Set the sous vide cooker to 133°F/56.2°C. If you are using a cooker with a circulator close the rear pump flow switch and set the front switch to fully open. When the water bath reaches temperature add the vacuum bag and cook for at least 1 hour, but it will not overcook the meat to leave it in the water for up to 4 hours.

While the fillet is slow cooking make your choice of topping.

For the Ragout: combine the wild mushrooms and hot water in a small bowl and set aside for 10 minutes.

Add the butter to the skillet that you used to brown the meat and heat over medium-high heat until foamy.  Add the shallots and the chopped mushrooms and sauté until the mushrooms brown a little, about 5 minutes.

Add the soaked mushrooms and their soaking liquid and the wine.  Bring to a boil and boil for 1 full minute to evaporate excess alcohol. Stir in the tomato sauce and the beef broth and simmer until the sauce thickens slightly, about 5 minutes.  Adjust seasoning with salt and pepper; set aside

For the Tomato Concasse: Chop the tomatoes into a coarse paste and stir in the basil and balsamic; set aside.

For the Jalapeno Gorgonzola Butter: Remove the stems and seeds from the peppers. Chop finely and combine with the other ingredients; set aside. 

When the fillet roast is done cooking, remove the pouch from the water bath, snip open one end, slip the roast onto a carving board and carve into thin slices. Because the meat is at perfect serving temperature and doesn't need to firm before slicing there is no need to rest the meat. 

If serving with mushrooms, heat the ragout to a simmer over medium high heat.  Stir in the parsley and spoon over the steaks.  Serve immediately.  If serving with the other toppings, decorate with small spots of composed butter and/ or concasse and serve the rest on the side.

Sous Vide Fillet Roast spotted with Jalapeno Gorgonzola Butter and Tomato Concasse
Photograph by A. Schloss