Preheat the oven to 375°F (190°C), making sure it is hot to ensure even baking.

In a large frying pan over medium-high heat, cook the ground beef or turkey until browned. Drain off excess fat.

Add the chopped onion and chopped garlic to the pan with the cooked meat. Sauté for 2-3 minutes until the onion is translucent.

Stir in the marinara sauce and cook for about 10 minutes. Add salt, pepper, dried oregano and dried basil. Remove from the heat.

In a separate bowl, mix the ricotta cheese, egg and grated Parmesan. Mix well.

To prepare the lasagne, spread a small amount of the meat sauce in the bottom of a 9x13-inch baking dish.

Layer the zucchini slices on top of the sauce. Spread a layer of the ricotta mixture and sprinkle with mozzarella cheese. Repeat the layers until all the ingredients are used up, finishing with a layer of meat sauce on top.

Cover the baking dish with aluminum foil and bake in the preheated oven for 30 minutes.

Remove the foil and continue baking for another 10 minutes or until the cheese is bubbly and slightly browned.

Let the zucchini lasagne cool for a few minutes before slicing and serving. Garnish with fresh basil leaves, if desired.