Preheat your oven to 375°F (190°C).
Sprinkle salt over the zucchini slices and allow them to sit for 10 minutes to release moisture, then pat them dry.
In a large skillet, warm the olive oil over medium heat. Add the chopped onion and minced garlic; sauté until they become translucent.
Incorporate the ground beef into the skillet, cooking until it is browned while breaking it apart. Drain any excess fat.
Mix in the marinara sauce along with oregano, basil, salt, and pepper. Let the mixture simmer for 5 minutes.
In a separate bowl, blend the ricotta cheese with the egg, adding a pinch of salt and pepper.
In a baking dish, start with a thin layer of the meat sauce, followed by a layer of zucchini slices, the ricotta mixture, mozzarella cheese, and repeat the layers, finishing with mozzarella and Parmesan on top.
Bake the dish uncovered for 35-40 minutes, or until it is bubbly and golden on top.
Allow the lasagna to stand for 10 minutes before serving.
