Place steak, garlic and onion in a large skillet on medium heat.
Stir frequently, seasoning generously with salt and pepper, until beef is browned.
Add sliced mushrooms, ¾ of chopped parsley, Worcestershire sauce and wine.
Continue to cook until it reaches a bubbly boil; cover and simmer on low heat ~30 minutes (this is a patient simmer; you may choose to simmer longer).
Heat three quarts of water to boiling, add pasta and boil according to package instructions, drain.
Keeping saucepan on low heat, add cream cheese; cover and simmer until cheese is melted, ~5 minutes.
Add remaining fresh parsley; stir to incorporate cream cheese and parsley; remove from heat.