Mix the salt, egg, and potato puree. Mix in the flours. Knead the dough for 8-10 minutes or until the dough is smooth. Cover and rest for 30 minutes. Make a 50/50 mix of flour and semolina. Divide the dough into 6 parts. Working with one piece at a time, roll the dough into sheets. Dust the dough with the 50/50 flour mix when it starts to get sticky. If using a pasta roller roll to the #2 thickness setting or about an 1/8 of an inch. Keep sheets covered while not in use.
Lay out one sheet of dough. With a 2 1/2 inch cutter mark the dough without cutting through. Use a 1/2 tablespoon measure to scoop the filling and place it in the center of each circle. Lay another sheet on top. Press around the goat cheese to seal the ravioli. Squeeze out any air bubbles. If the pasta doesn't seal, brush the inside with water or egg wash. Use the cutter to cut the ravioli. Place the ravioli on a sheet pan dusted with 50/50 flour. Keep covered until ready to cook. The ravioli can be refrigerated for up to 5 days or frozen for a month.
After the pancetta is cooked, bring a large pot of salted water to a boil. Add the ravioli to the water and cook for 5 minutes. Strain the pasta from the water and add to the sauce.