Mix all the ingredients for the dough and work it until smooth and it has an even consistency (with a mixer or by hand- note: If the dough is too dry, add a little water).
Cover it with plastic wrap and let it rest while preparing the filling.
Cook the spinach and squeeze out the extra water.
Chop it with a sharp knife.
Mix it with the ricotta cheese.
Add the egg.
Add the grated cheese, salt and pepper plus nutmeg.
Make sure all ingredients are mixed well together.
Preheat oven to 375°F.
Divide the dough in two.
Make two circles (12" each) using a rolling pin.
Place the 1st circle on parchment paper.
Spread some breadcrumbs on it.
Place part of the filling in the center of the circle.
Place the remaining filling in a ring around the center circle (close to the edges of dough-picture the planet Saturn when doing this! :) )
Cover it with the 2nd circle of dough.
Moisten and seal the borders using a fork.
Place a small bowl over the filled bump in the center.
Using a sharp knife cut the outside ring in 1" slices.
Turn each slice on its side (the filling becomes visible).
Remove bowl over center and poke gently with a fork..
Bake for 30 minutes in preheated oven at 375F.