- In a skillet over medium-high heat, soften the zucchini and garlic in half of the butter for 5 minutes. Season with salt. In a sieve set over a bowl, let the zucchini mixture drain and cool for 10 minutes, pressing down to extract as much water as possible. Transfer the zucchini mixture to a bowl.
- Add the ricotta, Parmesan and half of the lemon zest to the bowl of zucchini. Mix well with a spatula. Adjust the seasoning. Transfer the mixture into a pastry bag fitted with a ½-inch (1 cm) plain tip. Refrigerate the filling while preparing the pasta.
- On a floured work surface, divide the fresh pasta dough into 4 pieces and form each one into a rectangle. Using a pasta machine, roll one rectangle of dough at a time. Do not add too much flour so that the dough remains slightly sticky. Gradually flatten the dough to the 7, 8 or 9 setting, depending on your machine. Place the rolled dough on a very lightly floured surface. Cover with a clean dishcloth or plastic wrap to prevent from drying out.
- Using a 4-inch (10 cm) round cookie cutter, cut one piece of rolled dough at a time into circles (see note). Pipe about 2 tsp of the filling at the centre of each dough circle. Using a pastry brush, moisten the edges of the dough with a small amount of water and fold over into a half-moon around the filling. Tightly seal the edges. Place on a baking sheet lined with parchment paper.
- In the same skillet used to cook the zucchini or in a small pot, bring the broth to a boil for 2 minutes. Whisk in the remaining butter. Keep warm while you cook the pasta.
- In a pot of salted boiling water, cook half of the mezzelune at a time for about 2 minutes or until al dente. Remove with a slotted spoon and set aside on an oiled baking sheet.
- Serve the mezzelune in shallow bowls. Cover with the hot broth and garnish with the remaining lemon zest, more Parmesan and a few basil leaves.
You can re-roll the pasta dough scraps or use to make maltalgliati (irregularly shaped pasta).