Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking dish.

In a large skillet, brown the ground beef and Italian sausage together for 8 to 10 minutes.

Add the diced yellow onion and cook until softened, about 2 to 3 minutes. Stir in the minced garlic and red pepper flakes, cooking for 30 seconds.

Pour in the marinara sauce, stir in oregano, salt, and black pepper, and simmer the sauce for about 10 minutes.

Bring a large pot of salted water to a boil and cook the lasagna noodles for 2 minutes less than package instructions.

In a mixing bowl, combine the cottage cheese, egg, grated Parmesan cheese, chopped parsley, salt, black pepper, and nutmeg.

Spread a thin layer of meat sauce on the bottom of your greased baking dish. Layer 4 noodles, half cheese mixture, then half remaining meat sauce. Repeat and finish with noodles and meat sauce.

Sprinkle mozzarella and Swiss cheese evenly over the last layer of meat sauce. Cover tightly with foil.

Bake for 35 to 40 minutes. Remove foil for last 5 minutes to brown the top.

Let the lasagna rest for about 10 minutes before slicing.