Begin by boiling a large pot of salted water. Add lasagna noodles and cook according to package instructions, typically 8 to 10 minutes. Drain and set aside.

In a large skillet, heat olive oil over medium heat. Add ground beef and cook until browned, about 5 to 7 minutes. Stir in marinara sauce and diced tomatoes, simmer for about 10 minutes, and season with salt and pepper.

In a medium bowl, combine ricotta cheese, egg, and grated Parmesan cheese. Mix until smooth and creamy.

Preheat oven to 375°F (190°C). Spread a thin layer of meat sauce at the bottom of a baking dish. Layer with noodles, ricotta mixture, and mozzarella cheese. Repeat and finish with meat sauce and more mozzarella.

Cover with foil and bake for 25 minutes. Remove foil and continue baking for another 20 minutes until bubbly and golden brown.

Let the lasagna rest for 10 minutes, then slice and serve garnished with fresh basil or parsley.