My family has been eating some kind of lasagna on Christmas Eve every year since I can remember. While I've occasionally made a legit lasagne Bolognese, the family favorite is Italian-American-style, made with sausage-spiked Marcella Hazan tomato sauce, ricotta-spinach filling, and lots of fresh mozzarella. Because I'm usually feeding at least 10 people on Christmas Eve, I always make the lasagna in a roasting pan. There are always leftovers, but they're delicious for days, especially when you're sick of eating cookies. Like any lasagna, you can make this one in stages. The sauce can be made up to three days ahead and the assembled lasagna can sit in the fridge up to overnight before cooking. You can easily make the lasagna vegetarian by omitting the sausage and gluten-free by using gluten-free pasta. I've also made a separate side dairy-free "lasagna" by layering the sauce, noodles, and spinach in a loaf pan and baking it alongside the big one.