Be careful to initially undercook the pasta as it will continue to cook once it's in the oven. Traditionally, this dish calls for the addition of chicken liver, but it is less commonly used these days. If you want to add chicken liver, feel free to do so, just add at your discretion when the ground meat is almost browned and cook for approximately 5 minutes longer before adding the tomato. Since the sauce used to make imqarrun il-forn is a simple ragù, if you already have a favorite ragù recipe, feel free to incorporate your favorite elements of it, just make sure that the overall quantity of sauce and the volume of tomato is about the same so that the macaroni bake doesn't come out dry.