Slice your beef into thin, even strips. Season the meat generously with salt, pepper, and half of the smoked paprika. Mix it well so every piece is coated. This ensures flavor in every single bite.

Heat olive oil in a large pan over high heat. Add the beef strips in small batches. Sear them quickly for about 30 seconds per side. Remove the meat and set it aside on a plate.

Lower the heat and add butter to the same pan. Toss in the sliced onions and mushrooms. Cook them until they are soft and golden brown. This usually takes about five to seven minutes.

Stir in the minced garlic and the remaining smoked paprika. Add the tomato purée to the pan. If you are using brandy, pour it in now. Let the alcohol bubble away for a minute.

Pour in the beef stock slowly while stirring. Let the liquid simmer until it reduces by half. This step makes the sauce thick and full of beefy flavor. It should look dark and rich.

Turn the heat down to low. Stir in the sour cream until the sauce is smooth. Return the cooked beef and its juices to the pan. Warm it through gently but do not let it boil.

Taste the sauce and add more salt if needed. Sprinkle the freshly chopped parsley over the top. Serve it immediately while it is hot and creamy. Your kitchen will smell absolutely amazing now!