Sous Vide Steak with Porcini Butter and Wild Mushrooms

Place half of the dried mushrooms in a small bowl, cover with hot tap water and soak for 10 minutes. Drain well, removing as much liquid as possible from the mushrooms. Finely chop the soaked mushrooms and set aside.

Place the remaining dried mushrooms in a spice grinder or a small food processor and grind to a fine powder. In a small bowl, stir together the butter, chopped and powdered mushrooms, garlic, 1 tsp. kosher salt and 1/2 tsp. pepper until thoroughly blended. Cover and refrigerate for at least 30 minutes or up to 3 weeks.

Bring the steak to room temperature and season generously on both sides with kosher salt and pepper. Prepare an immersion circulator for use according to the manufacturer’s instructions. Preheat the water to 129°F (54°C) for medium-rare or 134°F (57°C) for medium.

Place the steak in a vacuum bag and add 3 Tbs. of the porcini butter and 4 of the thyme sprigs. Vacuum seal the bag.

When the water reaches the desired temperature, lower the bag into the water bath and clip the top of the bag to the side of the water basin. Cook the steak for 1 hour. (The steak can be left in the water bath, at the cooking temperature, for up to another 3 hours before serving.)

About 20 minutes before you want to serve the steak, in a large cast-iron fry pan over medium-high heat, melt 2 Tbs. of the porcini butter with the olive oil until foaming. Add the wild mushrooms and cook, stirring occasionally, until starting to soften and brown, about 7 minutes. Add the wine and cook, stirring, until evaporated, 1 to 2 minutes. Season to taste with kosher salt and pepper. Transfer the mushrooms to a plate. Wipe the pan clean.

Remove the bag from the water bath, transfer the steak to a plate and discard the thyme sprigs. Pat the steak dry and season with kosher salt and pepper.

In the same cast-iron pan over high heat, warm the canola oil until very hot. Add the steak and sear, turning once, until a charred crust forms on both sides, about 2 minutes per side. Add the remaining porcini butter and thyme sprigs to the pan and baste the steak with the butter for about 1 minute. Discard the thyme sprigs.

Transfer the steak to a cutting board and let rest for 5 to 10 minutes. Cut the steaks into slices and sprinkle  with flaky sea salt. Meanwhile, return the mushrooms to the cast-iron pan over high heat and cook, stirring occasionally, until heated through, about 1 minute. Serve the mushrooms alongside the steak. Serves 2.

Williams Sonoma Test Kitchen