In a mixing bowl, combine ricotta, Parmesan, mozzarella, spinach, nutmeg, egg yolk, salt, and pepper. Mix until smooth and creamy.

Roll out pasta sheets thinly. Cut them into 3×3-inch squares. Ensure they are even in size for uniform cooking.

Place 1 teaspoon of filling in the center of each square. Gather the edges and pinch them together at the top to form a pouch.

Bring a large pot of salted water to a boil. Drop the sacchetti gently and cook for 3–4 minutes until they float. Drain carefully.

In a pan, warm olive oil and add Alfredo or tomato sauce. Gently toss the cooked sacchetti in the sauce until coated.

Transfer to a serving dish. Garnish with extra Parmesan and fresh herbs. Serve hot.