01 - Preheat oven to 400°F. Line a baking dish with parchment paper or lightly grease it.
02 - Slice zucchini in half lengthwise. Using a spoon, scoop out the centers, leaving a 1/4-inch border to create boats. Reserve the scooped flesh and chop finely.
03 - Heat olive oil in a large skillet over medium heat. Add onion and cook for 2 minutes until softened. Add garlic and cook for 30 seconds.
04 - Stir in mushrooms and chopped zucchini flesh. Sauté for 4 minutes, until vegetables are tender and most liquid has evaporated.
05 - Add ground turkey, breaking it up with a spatula. Cook for 5-7 minutes, until browned and cooked through.
06 - Stir in salt, pepper, oregano, crushed red pepper flakes, parsley, and basil. Remove from heat and let cool for 2 minutes.
07 - Mix in half of the pesto and half of the Parmesan cheese into the turkey mixture.
08 - Arrange zucchini boats in the prepared baking dish. Spoon the turkey-mushroom filling evenly into each boat.
09 - Drizzle remaining pesto over the stuffed boats and sprinkle with remaining Parmesan. Cover loosely with foil and bake for 20 minutes.
10 - Uncover and bake an additional 5-10 minutes, until zucchini is tender and tops are golden. Garnish with extra herbs and serve hot.