Start by bringing a medium saucepan filled with salted water to a boil. Add the mini fussili pasta and cook until very al dente, about 5 to 7 minutes. Drain the pasta and set it aside.
In the same saucepan, no need to clean it out, set over medium heat, combine the water, chicken broth, and lemon juice. Bring the mixture to a simmer.
Add salt and pepper to the broth to taste. Remember, since you’re using low-sodium broth, you might need to adjust accordingly.
Turn the heat to low. Mix in the finely grated Parmesan-Reggiano, creating a rich and creamy broth.
Use a spoon to create a whirlpool in the broth. In a slow and steady stream, pour in the beaten egg to form delicate strands.
Mix in the fresh baby spinach, stirring until it wilts slightly.
Add the reserved fussili pasta back into the soup and adjust the seasoning to taste.
Divide the soup among bowls, garnishing with additional black pepper and strips of Parmesan before serving hot.
