Bring a large pot of salted water to a boil. Cook the lasagna noodles according to package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the chopped onion and garlic, sautéing until soft and fragrant.
Add the ground beef to the skillet, breaking it apart with a spatula. Cook until browned, about 5-7 minutes. Drain excess fat if necessary.
Stir in the crushed tomatoes, tomato paste, dried basil, dried oregano, salt, and pepper into the beef mixture. Let the sauce simmer for about 10-15 minutes to thicken.
In a separate bowl, combine the ricotta cheese with the egg, mixing well. Season with a pinch of salt and pepper.
Begin assembling the lasagna: spread a thin layer of meat sauce on the bottom of a 9x13-inch baking dish. Place a layer of lasagna noodles over the sauce.
Spread a portion of the ricotta mixture over the noodles, followed by a layer of mozzarella cheese, then another layer of meat sauce. Repeat the layers until all ingredients are used, finishing with a layer of noodles topped with the remaining meat sauce and the rest of the mozzarella and Parmesan cheeses.
Cover the baking dish with aluminum foil (without touching the cheese) and bake in the preheated oven for 25 minutes.
Remove the foil and bake for an additional 15-20 minutes, or until the top is golden and bubbly.
Once done, remove from the oven and let it sit for about 10-15 minutes before slicing to allow the layers to set.
Notes
Serve the lasagna slices on individual plates. Garnish with freshly chopped basil leaves and a sprinkle of Parmesan cheese for an elegant touch.