To make the filling, put the ricotta in a sieve for 3 to 4 hours to drain off any excess liquid

It should be as dry as possible for the filling

In a bowl, com- bine the ricotta, pesto, egg yolk, and salt and pep- per, forming an even mixture

Set it aside in the refrigerator, covered, until you are ready to use it. Roll out fresh tomato pasta dough into 2-inch by 8-inch strips about 1/16-inch thick

Working with one strip of dough at a time, space little mounds of filling (generous 1/2 teaspoonfuls) 2 inches apart in rows on the strip of pasta

With your fingers, moisten the dough around each mound of filling with a little water

Place a second sheet of dough on top of the first and with your hands, press firmly all around the mounds of filling to seal the sheets together

With a knife or, preferably, a fluted- edged pastry wheel, cut each ravioli strip into four 2-inch by 2-inch raviolis

Press down all around the edges of each ravioli while the dough is still very soft to assure that each is well sealed

Work very quickly to prevent the dough from drying out. Bring the broth to a boil, drop in the ravioli and cook about 3 minutes

Remember that they will continue to cook in the hot broth off the heat

Serve in flat soup dishes garnished with parsley and pass with freshly grated Parmesan

Serves 4 to 6.