1-First, prepare your ingredients by slicing the beef into thin strips, chopping the onion, slicing the mushrooms, and mincing the garlic. This setup, often called mise en place, keeps things organized and prevents any last-minute rushes. Once ready, heat the oil in a large pan over medium-high heat to start building that flavorful base.

2-Next, cook the beef strips in the hot oil for about 1 minute per side until browned, doing this in batches to avoid crowding the pan. Set the beef aside to keep it warm, as this helps maintain its tenderness. In the same pan, add the butter, onion, and mushrooms, sautéing them for 6-8 minutes until soft and lightly browned.

3-Then, stir in the garlic and cook for another minute until it smells great. Add the flour and mix it in, cooking for a minute to thicken things up. Pour in the beef broth and cream, scraping the pan to get all those tasty bits, and let it simmer for 1-2 minutes.

4-After that, temper the sour cream by mixing it with a bit of the sauce, then add it back in along with the Worcestershire sauce, mustard, salt, and pepper. Let everything simmer until creamy, then return the beef to the pan to heat through gently.

5-Finally, garnish with green onion or parsley and serve over egg noodles. For a twist, try pairing it with other easy dishes like our turkey carcass soup for a complete meal plan.