01 - Preheat the oven to 400°F. Line a baking dish with parchment paper or lightly grease it.
02 - Slice the zucchini in half lengthwise. Using a spoon, scoop out the centers to create boats, leaving about 1/4 inch thick shells. Reserve the scooped flesh and chop it finely.
03 - Heat olive oil in a large skillet over medium heat. Add onion and cook for 2–3 minutes until softened. Add garlic and cook for 30 seconds.
04 - Add ground turkey and cook, breaking up the meat, until browned and cooked through, about 5–7 minutes.
05 - Stir in mushrooms and reserved zucchini flesh. Cook for 3–4 minutes, or until the vegetables are tender and moisture has mostly evaporated.
06 - Stir in the pesto, Italian herbs, salt, and pepper. Remove from heat.
07 - Place zucchini boats in the prepared baking dish. Fill each with the turkey-mushroom mixture. Top with mozzarella and Parmesan cheese.
08 - Bake for 18–20 minutes, until the zucchini is tender and the cheese is golden and bubbling.
09 - Remove from the oven. Let cool for a few minutes before serving.