Divide the dough into two equal portions. Roll each into a rectangle, 1/8-inch thick. Let rest in a cool place. Squeeze all excess water from the spinach. In a bowl, combine it with the two cheeses, egg yolks, flour, salt, pepper and grated lemon rind.

Either spoon the filling or pipe it, in little walnut-size mounds at 1/2-inch intervals along one half of the dough. Brush with water between the fillings and cover with a second layer of dough. Mark the dough over the fillings with a pastry cutter turned upside down. Then, using a ruler and a serrated pastry wheel or ravioli cutter, cut the ravioli into squares. Line a baking sheet with wax paper and sprinkle with uncooked semolina. Place the squares on it and dry for 1 hour.

Bring a large pot of water to a boil. Add the ravioli and boil for 8 minutes. Refresh in cold water and drain. Preheat the oven to 375 degrees. Make the sauce by combining the tomato sauce and mushrooms. Place the ravioli in a buttered casserole and cover with sauce. Bake for 20 minutes.

Serve with: Stuffed Green Pepper Salad