This recipes has been in my family forever. It reminds me my childhood more than anything else.
In this recipe the pasta is raw so the sauce needs to be quite watery to allow the lasagne sheets to cook in it while in the oven. If you have a thick Bolognese sauce you can quickly boil the lasagne sheets before assembling the lasagne. Just don't make it cook more than 3 minutes, otherwise once out of the oven they will be overcooked.