Creating Gordon Ramsay Beef Stroganoff is a delightful experience when you follow these simple steps:

1. Prepare the Beef: Thinly slice the beef sirloin or tenderloin against the grain for tenderness. Season with salt and pepper.

2. Sauté the Beef: In a large skillet over medium-high heat, add 1 tablespoon of olive oil. Once hot, add the beef. Sear for about 2-3 minutes until browned, then remove from the pan and set aside.

3. Cook the Onions and Garlic: In the same skillet, add the remaining tablespoon of olive oil. Toss in the chopped onion and sauté until translucent, about 4-5 minutes. Add the minced garlic and cook for an additional 30 seconds until fragrant.

4. Add Mushrooms: Stir in the sliced mushrooms and cook until they release their moisture and are lightly browned, about 5-7 minutes.

5. Thicken the Sauce: Sprinkle the flour over the mushroom mixture, stirring to coat. Cook for about a minute to eliminate the raw flour taste.

6. Make the Sauce: Gradually pour in the beef stock, stirring continuously to prevent lumps. Add the Dijon mustard and Worcestershire sauce. Bring to a simmer and let it cook for 5 minutes until the sauce thickens.

7. Incorporate the Beef: Return the cooked beef to the skillet. Stir in the sour cream and mix until well combined. Cook for an additional 2-3 minutes until heated through. Adjust seasoning with salt and pepper as desired.

8. Garnish: Remove from heat and sprinkle with chopped fresh parsley for a touch of color and flavor.

9. Serve: Spoon the Beef Stroganoff over cooked egg noodles or rice, ensuring each plate is generously coated in the rich sauce.