Bring a pot of water to a boil and cook the egg noodles according to package instructions until al dente.
While noodles cook, slice the beef sirloin into thin strips and season with sea salt and black pepper.
Heat the olive oil in a large skillet over medium-high heat and sear the beef strips until browned, then remove from the pan and set aside.
In the same skillet, add the sliced mushrooms and diced onions, sautéing until the mushrooms are golden and onions are translucent.
Add the minced garlic and smoked paprika to the skillet, cooking for 1 minute until fragrant.
Pour in the beef broth and Dijon mustard, scraping the bottom of the pan to release any browned bits, and simmer for 2 minutes.
Reduce heat to low, return the beef to the skillet, and stir in the cooked egg noodles.
Remove the skillet from the heat and fold in the Greek yogurt until the sauce is creamy and well-combined.
Garnish with freshly chopped parsley and serve immediately.