Let’s dive into the cooking process. Follow these steps for a dish that’s sure to impress:

1. Heat the olive oil in a large pan over medium-high heat. Add the beef slices and season with salt and pepper. Sear the beef until browned on all sides, about 2-3 minutes. Remove from the pan and set aside.
2. In the same pan, add the chopped onion and cook until softened, about 5 minutes. Stir in the garlic and mushrooms, cooking until the mushrooms release their moisture and begin to brown, around 5-7 minutes.
3. Add the Dijon mustard and beef stock, stirring to combine. Let the mixture simmer for 5 minutes to allow the flavors to meld.
4. Reduce the heat to low and stir in the sour cream, ensuring it’s fully incorporated. Return the beef to the pan, gently folding it into the creamy sauce.
5. Let the stroganoff simmer on low for another 5 minutes, allowing the beef to heat through. Taste and adjust seasoning if necessary.
6. Serve the stroganoff over cooked egg noodles or rice, garnished with fresh parsley for a pop of color and flavor.

As my abuela always said, “A dish is only as good as the care put into it,” so take your time and enjoy each step!