In a large skillet, heat olive oil over medium heat. Add the chopped onion and garlic, sautéing until translucent, about 3-4 minutes.
Add the sliced mushrooms to the skillet and cook until they are softened and release their moisture, about 5-6 minutes.
In a bowl, mix the Greek yogurt, chicken broth, Dijon mustard, paprika, dried thyme, salt, and pepper until well combined.
Place the chicken breasts at the bottom of a baking dish and pour the mushroom mixture over the chicken, ensuring they are well coated.
Pour the yogurt sauce over the chicken and mushrooms, spreading it evenly.
Cover the baking dish with aluminum foil and bake for 25 minutes.
Meanwhile, cook the egg noodles according to package instructions until al dente. Drain and set aside.
After 25 minutes, remove the foil and bake for an additional 15 minutes, allowing the top to become slightly golden.
Once baked, remove from the oven and let it cool for a few minutes. Serve the baked chicken stroganoff over the cooked egg noodles and garnish with fresh parsley.