1 ½ pounds
chuck or sirloin steak, fat trimmed and sliced into ¼-inch-thick strips
2 teaspoons
kosher salt, divided
2 tablespoons
extra-virgin olive oil
4 tablespoons
unsalted butter
1
medium yellow onion, diced
2 pounds
white or cremini mushrooms, sliced
2
cloves garlic, minced
¼ cup
flour
2 cups
beef broth
1 tablespoon
fresh thyme, minced
¼ teaspoon
freshly cracked black pepper
1 tablespoon
Worcestershire sauce
½ cup
sour cream
1 tablespoon
Dijon mustard
Cooked pasta or mashed potatoes, for serving
Fresh parsley, finely chopped, for serving (optional)
Method
Season the steak all over with 1½ teaspoons of the salt.
In a large skillet, heat 1 tablespoon of the olive oil over medium-high heat. Working in small batches, add the steak and cook, undisturbed, until browned, 1 to 2 minutes per side. Transfer to a plate. Repeat with the remaining steak, adding remaining olive oil as needed.
Reduce the heat to medium. Add the butter to the same skillet. Once the butter has melted, add the onion and mushrooms and cook until the onion softens and the mushrooms are starting to brown, about 5 minutes. Add the garlic and cook, stirring, until fragrant, for 1 more minute.
Stir in the flour and cook, stirring, for 1 minute. Slowly pour in the beef broth and stir until fully incorporated. Add the thyme, remaining ½ teaspoon salt and pepper and simmer, stirring often, until the mixture is starting to thicken, about 5 minutes. Stir in the Worcestershire sauce, sour cream and Dijon mustard, until the sauce is combined. Bring the sauce to a gentle simmer and cook until the sauce is thick enough to coat the back of a wooden spoon. Return the meat to the skillet and toss until fully coated.
Serve over pasta of your choice or mashed potatoes and sprinkle with parsley, if using.
