- In a bowl, combine the ricotta and egg yolk with a spatula. Add ¼ cup (40 g) of the flour, the Parmesan and nutmeg. Mix until smooth. Lightly season with salt.
- Place ½ cup (75 g) of the flour in a large airtight container.
- Form the cheese mixture into balls using about 2 tsp for each one. Finish rolling the balls between your hands and place in the container with the flour. Sprinkle the remaining flour over the balls. Mix gently to coat the gnudi with the flour. Cover and refrigerate for 2 days, shaking the container a few times to ensure the gnudi are well coated with the flour.
- In a large non-stick skillet over medium heat, cook the squash in 2 tbsp of the butter for 7 minutes or until tender and lightly golden, stirring often. Season with salt and pepper. Set aside on a plate.
- Add the remaining butter to the skillet and cook until foaming. Add the sage leaves and brown for 1 minute or until crispy and the butter is browned and fragrant. Drain the sage leaves on paper towels. Return the squash to the skillet. Keep warm.
- Remove the gnudi from the flour. Place in a sieve to shake off any excess flour.
- In a large pot of lightly salted simmering water, cook the gnudi for 3 minutes or until they float to the surface. Using a slotted spoon, remove the gnudi from the water and divide among four plates.
- Top with the squash, browned butter, hazelnuts and sage leaves. Sprinkle with Parmesan.
In Italian, gnudi refers to naked pasta. Gnudi are similar to gnocchi but are not made with potatoes. de terre.