Bring a saucepan filled with water to a boil. Add lasagna noodles and cook till al dente. Drain and rinse with cold water.
In a large skillet, cook the sausage and beef over medium heat until no longer pink.
Drain all but 2 tablespoons of the grease and add the diced onions. When soft, add in the sauce.
In a medium bowl, combine the Ricotta, 2 cups of the mozzarella, egg and Italian seasoning. Mix well.
Layer as follows: 1/3 of the meat-sauce mixture, 3 cooked noodles, 1/3 of the cheese mixture. Do this three times.
Top with any extra sauce, 1 cup of mozzarella cheese and the Parmesan cheese.
Cover with foil and bake in the preheated oven for 30 minutes. Remove the foil and bake for an additional 20 minutes.
Cottage cheese can be substituted for ricotta cheese if you don’t have it or prefer a different texture.