This juicy, tasty beef smothered in creamy sauce is a crowd pleaser.
Dredge beef in flour. Make sure all pieces are coated well.
In a pan, melt butter then sauté onions until tender. Add beef slowly. Mix well. Add mushrooms, tomato paste and beef stock. Lower heat and bring to simmer.
Add Worcestershire sauce, salt and pepper. Simmer covered over low heat until beef is tender.
Add sour cream and cheese. Simmer once.