Get Everything Prepared: Chop the beef into chunks. Do the same with the onion and mince the garlic, too. The mushrooms need some slicing love.
Mix It All: Throw the beef, onion, garlic, and mushrooms into your slow cooker. Add beef broth, Worcestershire sauce, and Dijon mustard. Sprinkle on salt and pepper for good measure.
Let it Cook: Toss that rosemary sprig on top like a chef. Pop the lid on and cook either on low for 8 hours or crank it up on high for 4 hours.
Add Some Creaminess: About 20 minutes before you’re ready to chow down, remove the Rosemary and stir in the cream cheese until it melts into creamy goodness. Sour cream is a good stand-in if you’d like.
Noodle Time: As the cream cheese works its magic, cook the egg noodles according to the package directions.
Let’s Eat: With noodles cooked and stroganoff ready, plop a hearty serving over the noodles. Sprinkle on some fresh rosemary if you’re feeling fancy.