Buy the ingredients
Brown the beef.
"I put about 1/3 cup of sauce in the bottom of a smaller pyrex. I spread about half of the ricotta mixture (ricotta, a couple ounces shredded mozzarella, herbs, egg) on several pieces of chicken and placed it on top of the sauce. Top with half of the beef, some spinach, and a bit more sauce. Top all of that with the sliced mozzarella. Repeat these layers, ending with a saucy layer covered with the rest of the shredded mozzarella."
Bake for a half hour at 400°F.