Steps

• Heat a large skillet over medium-high heat, add olive oil, and cook beef strips in batches until browned, about 2-3 minutes per side. Remove and set aside.
• In the same skillet, add more olive oil if needed, cook onions until translucent, add mushrooms, and sauté until browned, about 5 minutes. Add garlic and cook for an additional minute.
• Sprinkle flour over the mushroom mixture to create a roux, then gradually pour in beef broth while stirring. Reduce heat and mix in sour cream, Dijon mustard, and Worcestershire sauce until smooth.
• Return beef to skillet, simmer gently in the sauce until heated through, about 5-10 minutes. Season with salt and pepper, garnish with parsley, and serve over preferred side.