Brown the beef and aromatics. Heat your large skillet over medium-high heat and add the ground beef. Break it apart with a wooden spoon and cook until no longer pink, about 5 minutes. Add the diced onion and cook until translucent, about 3 minutes more. Add the minced garlic, Italian seasoning, and red pepper flakes (if using), and cook until fragrant, about 30 seconds.
Build your sauce base. Add the diced tomatoes with their juice, tomato sauce, and beef broth to the skillet. Stir to combine and bring to a simmer. Season with salt and pepper to taste.
Cook the noodles directly in the sauce. Break the lasagna noodles into roughly 2-inch pieces and add them to the skillet, making sure they’re all submerged in the liquid. Cover the skillet and reduce heat to medium-low. Let simmer, stirring occasionally to prevent sticking, until the noodles are tender, about 15 minutes.
Add the cheeses. Once the noodles are tender, stir in half of the mozzarella and all of the ricotta cheese until well combined. The sauce should be creamy and the ricotta fully incorporated.
Create that perfect cheesy top. Sprinkle the remaining mozzarella and all of the Parmesan over the top. Cover and cook on low heat for 2-3 minutes until the cheese is completely melted and slightly bubbly.
Finish with fresh herbs. Remove from heat, sprinkle with fresh chopped basil, and let stand for 5 minutes before serving. This brief rest allows the sauce to thicken slightly and flavors to meld.