Preheat your oven to 375°F (190°C) and grease a 9×13-inch baking dish.
Slice zucchinis into rounds, sprinkle with salt, and let sit for 15-20 minutes to draw out moisture.
In a skillet, heat olive oil over medium-high heat; sauté onion until softened. Add ground turkey, breaking it apart while browning. Drain excess fat and stir in garlic and herbs.
Incorporate diced tomatoes along with remaining salt and pepper; simmer for about 5 minutes.
Layer half of the zucchini in the baking dish, followed by half of the turkey mixture. Repeat layers.
Top with shredded mozzarella cheese and cover with foil.
Bake for 25 minutes covered, then uncover and bake for another 20-25 minutes until bubbly and golden.