Ingredients:

  • 1.5 lbs (680g) beef sirloin or tenderloin, cut into thin strips against the grain
  • 2 tablespoons olive oil
  • 1 medium yellow onion, finely chopped (about 1 cup)
  • 2 cloves garlic, minced
  • 8 oz (225g) cremini mushrooms, sliced
  • 1/2 teaspoon salt
  • 1/4 teaspoon black pepper
  • 1 tablespoon all-purpose flour (plus extra for dredging beef, about 2 tablespoons)
  • 1 cup (240ml) beef broth (low sodium preferred)
  • 1/4 cup (60ml) dry sherry (optional, but highly recommended!)
  • 1 tablespoon Dijon mustard
  • 1 teaspoon Worcestershire sauce
  • 1 cup (240ml) sour cream (full-fat, for best results)
  • 2 tablespoons chopped fresh parsley, for garnish
  • Cooked egg noodles, rice, or mashed potatoes (to serve)

Instructions:

  1. Dredge the beef strips in a small amount of flour seasoned with salt and pepper. This helps with browning and thickening the sauce.
  2. Heat olive oil in a large skillet over medium-high heat. Brown the beef in batches, being careful not to overcrowd the pan. Set aside.
  3. Add the chopped onion to the skillet and sauté until softened and translucent. Then, add the minced garlic and sliced mushrooms and cook until the mushrooms are tender and have released their moisture.
  4. Sprinkle 1 tablespoon of flour over the cooked vegetables and stir well. Cook for 1 minute to create a roux. Gradually whisk in the beef broth, scraping up any browned bits from the bottom of the pan. Stir in the sherry (if using), Dijon mustard, and Worcestershire sauce. Bring to a simmer.
  5. Return the browned beef to the skillet. Reduce the heat to low, cover, and simmer for about 15-20 minutes, or until the beef is tender.
  6. Remove the skillet from the heat and gently stir in the sour cream. Do not boil the sauce after adding sour cream, or it may curdle!
  7. Season with salt and pepper to taste. Garnish with fresh parsley and serve immediately over cooked egg noodles, rice, or mashed potatoes.