In a large skillet that has a lid, heat the olive oil over medium heat. When hot, add the onion plus 1 teaspoon kosher salt and cook for 4 minutes, stirring frequently until the onion is soft and slightly translucent. Add the garlic and crushed red pepper and cook for another minute or until the garlic is fragrant, but not browned. Crumble the ground beef and Italian sausage into the skillet, sprinkle with another teaspoon kosher salt, and cook, stirring frequently, until the meat is completely cooked.
Break the lasagna noodles into 1–2" pieces and spread over the meat layer. Add the water, crushed tomatoes, and tomato sauce. Bring to a boil, then cover with the lid, reduce heat to a simmer, and cook, stirring occasionally, for 20 minutes or until the noodles are cooked al dente.
While the noodles are cooking, combine the ricotta, 1/2 cup of parmesan, and 1/2 cup of mozzarella cheeses with 1/2 teaspoon kosher salt and 1/4 teaspoon freshly ground black pepper. When the pasta is completely cooked, dollop the ricotta cheese mixture over the meat and noodle mixture and sprinkle with the reserved parmesan and mozzarella. Remove from heat and cover the pan for 4–5 minutes or until the ricotta mixture softens and the other cheeses melt. Top with chopped fresh basil and serve.