Cook the beef in a large skillet over medium heat until it is browned and mostly cooked through. Remove any extra fat from the skillet before transferring.

Scoop the beef into the slow cooker. Add in the diced onion, garlic, sliced mushrooms, Worcestershire sauce, Dijon mustard, smoked paprika, salt, pepper and beef broth. Stir all the ingredients together gently until just combined.

Place the lid on the slow cooker and cook on low for 4-5 hours or on high for 2-3 hours.

30 minutes before servings, cube the cream cheese and place it into the slow cooker. Add in the cornstarch slurry and mix everything together gently. The cream cheese will begin to melt. Do a taste test and adjust the seasoning if you would like. Cover and cook for 20 more minutes.

Bring a large pot of water to a boil and cook the egg noodles according to the instructions on the package.

Turn the slow cooker off. When the noodles are cooked to al dente, place them in the slow cooker along with the sour cream. Gently fold everything together.

Serve right away with a sprinkle of fresh parsley.