In a large pot over medium heat, add 2 tablespoons of butter. Once melted, toss in 1 chopped onion, 2 diced carrots, and 2 chopped celery stalks. Sauté for about 5-7 minutes, stirring frequently, until the vegetables are softened and fragrant.

Stir in 2 minced garlic cloves and cook for an additional minute. Then, pour in 6 cups of chicken broth, scraping any browned bits from the bottom of the pot. Bring to a gentle simmer over medium-high heat for about 10 minutes.

Add 3-4 cups of shredded leftover turkey into the soup, stirring well to combine. Reduce the heat to medium-low, and gently stir in 1 cup of heavy cream. Allow to simmer for another 5 minutes.

Add 2 cups of egg noodles, stirring to ensure they're well distributed. Cook for about 8-10 minutes, or until the noodles are tender but al dente.

Once the noodles are cooked, taste and season with salt and pepper. If desired, stir in fresh parsley. Let simmer for an additional 2-3 minutes.

Ladle into bowls, garnishing with additional parsley if desired. Serve immediately.