Prepare the egg pasta sheets, the ragù (if it is frozen, thaw it over low heat), and the béchamel sauce;
Place a little béchamel onto the bottom of a casserole, then a sheet of pasta followed by a layer of béchamel and one of ragù;
Repeat this process until you have used up all the pasta sheets;
Top with thinly shredded Parmigiano Reggiano cheese;
Bake it in a static oven at 350°F (180°C) for 20 minutes. Once out of the oven, let it sit for a few minutes before serving.