Bring a large pot of salted water to a boil. Add 8 ounces of egg noodles and cook according to package instructions until al dente, usually about 7-8 minutes. Drain and set aside. Toss with a little butter or olive oil if desired to prevent sticking.
In a large skillet, heat 2 tablespoons olive oil over medium heat. Add the diced onion and cook for about 3-4 minutes until softened and translucent. Add the minced garlic and cook for another minute until fragrant but not browned.
Add the sliced mushrooms to the skillet. Sauté for 6-8 minutes, stirring occasionally, until they release their moisture and start to brown.
Pour in 1 cup of chicken or vegetable broth and 1 tablespoon Worcestershire sauce. Stir well, scraping any browned bits off the bottom of the pan. Let the mixture simmer for 5 minutes to reduce slightly and concentrate the flavors.
Lower the heat to medium-low. Add 1 cup of sour cream and 1 tablespoon of Dijon mustard. Stir gently until the sauce is creamy and smooth. Avoid boiling after adding sour cream to prevent curdling. Season with salt and pepper to taste.
Add the cooked egg noodles directly into the skillet with the mushroom sauce. Toss gently to coat the noodles evenly in the creamy sauce. Warm through for 1-2 minutes.
Sprinkle chopped fresh parsley over the top for a fresh, vibrant finish. Serve immediately and enjoy the comforting goodness!
