Bring a large pot of lightly salted water to a boil. Add egg noodles and cook according to package directions until al dente, about 8-10 minutes. Drain and set aside.

While the noodles cook, brown the ground beef in a large skillet over medium-high heat, breaking it into smaller pieces as it cooks.

Add chopped onion to the beef and continue cooking until onion becomes translucent, about 3-4 minutes. Add minced garlic and cook for another 30 seconds until fragrant.

Add sliced mushrooms to the skillet and cook until they release their moisture and begin to brown, approximately 4-5 minutes.

Stir in the condensed cream of mushroom soup and Worcestershire sauce, mixing well to combine. Reduce heat to low and simmer for 5 minutes.

Remove the skillet from heat and let cool slightly for 1-2 minutes before stirring in the sour cream. (This prevents the sour cream from curdling.)

Season with salt and pepper to taste.

Serve the creamy beef mixture over the cooked egg noodles, garnished with fresh parsley if desired.