Heat another tablespoon of oil in the same pot over med-low heat, add the onions and cook until softened, about 7 minutes.
1 tablespoon neutral vegetable oil, ½ onion
Add the mushrooms, salt, pepper and thyme and continue to cook until the mushrooms have released their liquid and are lightly browned.
1 pound cremini or white button mushroom, ½ teaspoon dried thyme, 1 teaspoon salt, 1 teaspoon paprika, ¼ teaspoon black pepper
Add the garlic and a quarter cup of flour. Stir constantly to distribute the flour throughout for about two minutes.
2 cloves garlic, ¼ cup all-purpose flour
Add the chicken broth and wine or vermouth and stir, scraping up any brown bits that have stuck to the bottom of the pan.
2 cups chicken or vegetable broth, ¼ cup white wine, vermouth, or brandy
Add the egg noodles and return the meatballs to the pot. Stir everything into the liquid, cover the pot, and cook for the time specified on your package of noodles, stirring a few times.
8 ounces wide egg noodles
Add the sour cream, Dijon mustard, and parsley and cook over low heat for 1 to 2 minutes to warm the dish through.
½ cup sour cream, 2 teaspoon Dijon mustard
Add salt and pepper to taste. Serve immediately, garnished with the chopped parsley.
salt and pepper to taste, ¼ cup parsley