Simmer the stock: Place stock in a 2-quart saucepan and bring to a simmer.
Whisk together the egg, Parmesan, and breadcrumbs: In a medium bowl whisk together the egg, Parmesan cheese, breadcrumbs (if using), and black pepper.
Stir in the spinach: Once the stock is simmering, stir in the sliced spinach.
Pour the egg mixture into the soup: Pour/scrape the cheese and egg mixture into the simmering stock, do not stir. After a few seconds, stir the mixture gently into the soup. Cook at a gentle simmer for another minute. Taste the soup and add more salt and pepper if you wish. Serve immediately. Did you love the recipe? Give us some stars and leave a comment below!
