Sear the Beef: Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Once hot, add the beef in batches to avoid overcrowding. Sear each side for about 1–2 minutes, just until browned. Remove the beef from the pan and set it aside.

Sauté the Aromatics: In the same pan, add the remaining olive oil. Sauté the chopped onions until soft and translucent, about 3–4 minutes. Add the minced garlic and cook for another minute until fragrant.

Add Mushrooms and Seasoning: Add the sliced mushrooms to the pan. Let them cook undisturbed for a couple of minutes to develop a nice golden color. Stir in the smoked paprika and Dijon mustard.

Deglaze and Simmer: Pour in the beef stock to deglaze the pan, scraping up any browned bits at the bottom. Let it simmer for 5 minutes, allowing the flavors to meld and the liquid to reduce slightly.

Stir in the Sour Cream: Lower the heat and stir in the sour cream. Mix well until the sauce becomes creamy and smooth. Be sure not to boil the sauce after adding the sour cream, as it may split.

Return the Beef: Add the seared beef back into the pan along with any juices. Stir gently to coat in the sauce. Let it heat through for about 2–3 minutes, just until warmed but still tender.

Serve and Garnish: Serve hot over egg noodles or rice. Sprinkle with fresh parsley and a pinch of cracked black pepper for a final touch.