Melt the butter in a large pot over medium heat.
Add the onions, carrots, and celery, and cook until softened, about 5 minutes.
Stir in the minced garlic, thyme, salt, and pepper, and cook for another minute until fragrant.
Pour in the chicken broth, bring it to a boil, then reduce the heat, cover, and let it simmer for about 15 minutes.
Remove the woody thyme stems and add the cubed turkey and egg noodles, and let the soup simmer until the noodles are tender, about 10 minutes.
In a separate bowl, whisk together the flour and 1/2 cup water until smooth, then stir in the heavy cream.
Slowly pour the cream mixture into the soup, stirring continuously to avoid lumps.
Simmer for an extra 2-3 minutes, allowing the soup to thicken.
Add the peas and cook for 1-2 more minutes, just until they’re heated through.
Finish by sprinkling with chopped parsley before serving.