Prepare the egg noodles according to the directions provided on the package. Drain them thoroughly once tender and set aside until ready to serve.
Warm the olive oil in a large skillet over medium-high heat. Add the ground beef and cook for approximately 5–7 minutes, using a spatula to break the meat into smaller pieces as it browns.
Add the finely diced onion to the browned beef and cook for about 3–4 minutes, or until softened. Stir in the sliced mushrooms and continue cooking for another 3–5 minutes, until the mushrooms become tender.
While the beef and vegetables cook, place the cottage cheese, sour cream, Dijon mustard, Worcestershire sauce, dried thyme, black pepper, and salt in a blender or food processor. Blend until completely smooth and creamy.
Pour the blended cottage cheese sauce into the skillet containing the beef, onion, and mushrooms. Stir until evenly incorporated, then add the beef broth. Bring the mixture to a gentle simmer, reduce the heat to low, and cook for approximately 10 minutes so the flavors can develop and the sauce can thicken slightly.
Spoon the creamy beef stroganoff over the prepared egg noodles, or gently toss the noodles with the sauce until evenly coated. Serve warm.