In a skillet over medium-high heat and add olive oil. Then add onion and sauté until transparent. Add paprika and black pepper and mix with the onion.
Add beef and brown all sides, add a few drops of water if needed. Once beef is browned, add mushrooms, tomato, water, hot pepper and salt. The longer the hot pepper cooks with the stewing beef, the spicier it will be.
Reduce heat, cover with lid and simmer slowly until tender, approximately 11/2 hours, stirring occasionally. The longer it cooks the more tender the beef will be and the liquid will reduce. If you want more liquid, add about 1/4 cup before adding sour cream mixture.
To avoid the sour cream from separating, set it out to room temperature. Then add the sour cream and flour into a small bowl, then add some of the sauce and blend with a wire whisk or fork until it has a smooth consistency. Turn the temperature to medium, not a hard boil, add the sour cream mixture and whisk until the sour cream is well blended. Cook for about 1-2 minutes until the sauce has thickened, adjust seasoning if needed, then remove the skillet from the heat.
Serve with homemade dumplings, egg noodles or your favourite pasta. Garnish with chopped parsley.