Begin by bringing a large pot of salted water to a boil. Add egg noodles. 

Let the egg noodles cook until they are al dente and then strain the water from the noodles. Rinse the noodles with cold water and set aside. 

Next, heat a large pan (or dutch oven) over medium/high heat and add ground beef and ½ teaspoon salt. 

Break the ground beef up in the pan with a wooden spoon. When the ground beef is almost cooked add the onion and garlic to the beef and mix. 

Cook all those ingredients together for 2-3 minutes or until the beef is fully cooked. 

Remove from the heat and remove beef from the pan and set aside. 

In the same pan, add 2 tablespoons of butter and heat over medium heat. 

When the butter is melted, add all of the mushrooms and ½ teaspoon of salt and turn the heat down to medium/low.

Let the mushrooms sauté for 6-8 minutes, tossing them every 3-4 minutes. 

Then, turn the heat up to high heat and let the mushrooms brown for 1 minute.

While the mushrooms are browning, measure out the beef broth and add the Worcestershire to the broth and whisk until combined. Set aside. 

Turn the heat to low and add the last 2 tablespoons of butter to the pan.

Toss the mushrooms in the melted butter and then sprinkle the flour over the mushrooms and toss again making sure the mushrooms are covered in flour. 

Turn the heat to medium/high heat and slowly pour beef broth into the pan and whisk consistently until the mixture thickens. 

Turn heat to low and add the fresh thyme to the pan and mix. 

When the fresh thyme is fragrant, remove the pan from heat. 

Add Greek yogurt, sour cream, and pepper and mix until combined. Add 1 or 2 tablespoons of additional beef broth to thin out, if needed.

Pour the ground beef mixture into the sauce and mix and return to the heat. Heat the mixture over low heat until it reaches the desired temperature. 

Fold the egg noodles into the ground beef sauce and let the mixture and serve.