Cook lasagna noodles in salted water until soft. Drain carefully and place them flat to prevent sticking together during preparation.

Heat olive oil in a frying pan. Add onions and garlic. Cook until soft and fragrant. Add ground beef and cook until nicely browned.

Pour marinara sauce into the beef mixture. Add salt, pepper and Italian seasoning. Stir well and let the sauce simmer gently for 10 minutes.

In a bowl, combine ricotta cheese, egg, and parmesan cheese. Mix until smooth and creamy. This creates the rich lasagna filling.

Spread a thin layer of meat sauce on the bottom of the baking dish. This prevents noodles from sticking while baking.

Place lasagna noodles over the sauce. Spread ricotta mixture evenly. Add meat sauce and mozzarella cheese on top.

Continue layering noodles, ricotta mixture, sauce and cheese until all ingredients are used. Finish with mozzarella cheese on the top layer.

Cover the baking dish with foil. Bake at 180°C for 35 minutes until hot and bubbly throughout the dish.

Remove the foil carefully. Bake another 10 minutes until the cheese becomes golden and slightly crispy on top.

Let the lasagna rest for 10 minutes before slicing. This helps the layers stay firm and neat when served.