Preheat your oven to 375°F (190°C).

In a large skillet, add the ground beef and Italian sausage, cooking until browned, about 8–10 minutes. Stir in the chopped onion and minced garlic, cooking until the onion is translucent. Drain any excess fat, then set the mixture aside.

Add crushed tomatoes, tomato paste, dried oregano, and basil to the skillet with the meat. Season with salt and pepper to taste. Let the sauce simmer on low heat for 30 minutes, stirring occasionally.

In a mixing bowl, combine the ricotta cheese, beaten egg, and a pinch of salt. Stir until the mixture is creamy and smooth.

In a 9x13 inch baking dish, begin layering your lasagna. Start with a layer of meat sauce, followed by lasagna noodles, a layer of the ricotta mixture, and a sprinkle of mozzarella cheese. Repeat until all ingredients are used, finishing with a top layer of mozzarella and Parmesan.

Cover the baking dish with foil and bake for 25 minutes. Remove the foil and bake uncovered for another 25 minutes until the top is golden and bubbly.

Once baked, remove the lasagna from the oven and allow it to cool for 15 minutes before slicing.