The final step to making lasagna is by far the most satisfying, because you can see it finally come together.
If you are organized and place all of your ingredients out in front of you, you can layer the lasagna while cooking your pasta. As I said before, the pasta cooks very quickly, so if you do decide to multi-task with this, you have to work quickly.
I like to add sausage to the lasagna so before layering it ( usually around the same time that I make the besciamella sauce, I sautee 1 lb of Italian sausage in a small frying pan. You don't need to put any oil in the pan, just remove the sausage from its casing and turn up the heat. Every once in a while break up the sausage with a wooden spoon, so that you get small crumbles as a final result. You want the pieces nice and brown and fully cooked.
Once everything is set you are almost ready to start layering. I usually place the sauces and sausage in separate bowls and have my baking pan all ready to go.
First, place a small layer of meat sauce on the bottom of the baking dish. This will prevent the pasta from sticking to the bottom. Place one layer of cold pasta in the dish, cover with meat sauce, besciamella, and a thin layer of sausage, top with another layer of pasta and repeat the steps until the baking dish is full.
If you are going to freeze the lasagna do so at this point ( before baking the lasagna).
preheat oven to 400 degrees
Place the baking dish on a sheet pan ( sometimes the sauce leaks out during cooking) and put them in the oven. Bake for 35 minutes. Add a layer of grated mozzarella cheese to the top of the lasagna. Bake for an additional 10 minutes, or until golden brown on top.
remove from oven and let sit for 5 minutes. Cut and enjoy!