Melt the butter in a large skillet over medium-high heat.
Add the mushrooms and onion, and cook, stirring often, until the mushrooms are tender and golden brown and the onions are softened, about 4-5 minutes.
Add the ground beef and cook until browned, about 4-5 minutes, making sure to break it up into crumbles as it cooks. Season with sea salt and freshly cracked pepper, to taste.
Add the garlic and fresh thyme leaves and cook, stirring constantly, for 1 minute.
Add flour and cook, stirring it into the mixture, until browned, about 2 minutes.
Add the wine and cook, scraping any browned bits from the bottom of the skillet.
Stir in the beef broth, Worcestershire sauce, Dijon mustard, and egg noodles; toss to coat evenly. Bring to a boil; cover, reduce to heat to low and simmer, until pasta is cooked through, about 9-10 minutes.
Stir in the sour cream until heated through, about 2-3 minutes. Taste and season with sea salt and freshly cracked pepper, to taste.
Sprinkle the top with fresh parsley. Serve immediately. Enjoy.