Boil water in a pot then add the salt and cook the pasta. In the meantime, preheat oven grill to the highest temperature.
Roughly cut the bologna, put it in a bowl and add the béchamel sauce. Drain the pasta and put it in the same bowl, stir, add pepper and transfer the mixture into a buttered casserole.
Spread parmesan on top and grill in the oven for a few minutes, until the surface of the gratin is golden. Serve the penne gratin as soon as they are ready.