Whisk the egg yolks with 20 g of water.

On a work surface add the egg yolk mixture to the flour, and whisk with a fork until incorporated.

Knead the dough until smooth and elastic adding additional water as necessary.

Wrap the dough in plastic wrap and set aside to rest for an hour.

Rinse the radicchio then pat dry.

Cut off an inch of the radicchio base and discard.

Core the radicchio.

Finely mince the core.

Slice the rest of the radicchio into very thin strips.

Cut the strips into half inch pieces.

Mince the scallion.

Wilt the radicchio and scallion in the olive oil for three minutes, stirring constantly.

Remove from the heat.

Cut the caciocavallo cheese into tiny cubes, about 3/8 cm (1/8 inch).

Mix the ricotta and caciocavallo cheese together.

Mix in the radicchio.

Salt and pepper the filling to taste.

Cut the pork jowl into very thin strips about 3/8 cm (1/8 incby 2 cm (3/4 inch).

Sauté the pork jowl in a nonstick pan over a very low flame until crisp and golden.

Add the sage leaves and cook until crisp but still very green.

Set aside eight chestnut halves to use as a garnish.

Simmer the remaining chestnuts in the broth for three minutes.

Use an immersion blender to cream the chestnuts and broth.

Set aside.

Knead the dough until smooth and elastic.

Roll out into very thin, 8 cm (3 incwide, strips. If you are using a pasta machine roll out the dough to the thinnest setting.

Place dollops of pasta filling along each pasta strip, about 2 1/2 cm (1 incapart.

Place another pasta strip on top and gently press the strips together around each mound of filling so that the two pasta strips are sealed and no air pockets remain around the filling.

Use a pasta cutter to cut out the ravioli shapes.

Set the excess pasta bits aside to use later for making soup.

Continue rolling out the pasta strips and making ravioli until the pasta and filling are finished.

Let rest on a lightly floured dish towel while the pasta water comes to a boil.

If you plan to freeze the ravioli:

Line the ravioli on baking sheets and place in the freezer.

Once the ravioli are frozen solid you can store them in airtight freezer bags for about six months.

Bring a large pot of water to a boil, about 5 L (5 quarts).

Add enough salt to the water so that it has a salty taste - similar to seawater.

Cook the ravioli until al dente - until the pasta is soft but not mushy, and still has a bite to it.

Use a teardrop strainer to scoop out the pasta; never use a colander for ravioli!

Homemade ravioli are delicate and a teardrop strainer is the perfect tool to avoid breaking the ravioli.

Gently fold the ravioli into the sauce pan with the guanciale and sage. I always use large silicone scraping spatulas for this.

Reheat the chestnut cream and spread a thin layer on each serving dish.

Top with ravioli, a few pork jowl strips and fried sage leaves.

Serve immediately.

Note: Cleaning, cooking and peeling chestnuts: This task is so time-consuming it often keeps me from preparing chestnut dishes. I strongly suggest that you purchase already peeled and cooked chestnuts for this dish. Here's where you can purchase them.