01 -
Bring the chicken broth to a gentle boil in a medium saucepan over medium-high heat.
02 -
Add the pastina pasta to the boiling broth and simmer for 6 to 8 minutes, stirring occasionally, until the pasta becomes al dente.
03 -
Reduce the heat to low. Slowly pour the beaten egg into the pot while whisking continuously to achieve a velvety, silky consistency throughout.
04 -
Stir in the butter and grated Parmesan cheese until both are fully melted and evenly incorporated. Taste and adjust seasoning with salt and freshly ground black pepper.
05 -
Ladle the soup into warm bowls. Garnish with additional Parmesan and a final grind of black pepper before serving.