01 - Preheat oven to 400°F. Line a baking dish with parchment paper or lightly oil it.
02 - Wash the zucchini and slice each in half lengthwise. Using a spoon, carefully scoop out the flesh to create boats, leaving about 1/2 inch shell. Reserve the scooped-out flesh and chop it finely.
03 - Heat olive oil in a large skillet over medium heat. Add onion and sauté 2–3 minutes until softened. Add garlic and cook 30 seconds.
04 - Add chopped mushrooms and reserved zucchini flesh. Sauté 5–7 minutes until the mixture is softened and moisture has mostly evaporated.
05 - Add ground turkey, salt, pepper, and oregano. Cook, breaking up the meat, until turkey is browned and cooked through, about 5–7 minutes.
06 - Remove pan from heat. Stir in the pesto until well combined. Taste and adjust seasoning if needed.
07 - Arrange zucchini boats in the prepared baking dish. Spoon the turkey-mushroom filling into each boat, pressing lightly.
08 - Sprinkle mozzarella and Parmesan evenly over the stuffed zucchini.
09 - Bake for 20–25 minutes or until the zucchini is tender and the cheese is golden and bubbling.
10 - Remove from oven and let rest for 5 minutes. Garnish with fresh basil and cracked black pepper if desired. Serve warm.