Bring a large pot of salted water to a boil and cook the egg noodles according to package directions. Drain and set aside.
Melt the butter in a large skillet over medium heat. Add the diced onion and cook for 3 minutes until it softens.
Stir in the sliced mushrooms and cook for 6 to 8 minutes until they release their liquid and start to brown.
Add the minced garlic and cook for 1 minute more.
Sprinkle the flour and paprika over the mushroom mixture. Stir well and cook for 1 minute to remove the raw flour taste.
Slowly pour in the vegetable broth while stirring to avoid lumps. Simmer for 4 minutes until the sauce thickens.
Remove the skillet from the heat and stir in the sour cream until smooth. Season with salt and black pepper.
Divide the cooked egg noodles among four plates and spoon the mushroom sauce over the top. Sprinkle with chopped parsley before serving.