Preheat your oven to 400°F and line a baking sheet with parchment paper.
Slice the zucchinis in half lengthwise and use a small spoon to scoop out the seeds and flesh, leaving a 1/4-inch thick shell.
Heat the olive oil in a large skillet over medium-high heat and sauté the diced onion and garlic until softened and aromatic.
Add the ground turkey to the skillet, breaking it up with a spatula, and season with oregano, salt, and pepper.
Once the turkey is browned and cooked through, stir in the tomato puree and simmer for 3 minutes to meld the flavors.
Spoon the turkey mixture generously into the hollowed zucchini boats and place them on the prepared baking sheet.
Sprinkle the grated parmesan cheese evenly over the tops of the stuffed zucchinis.
Bake for 20 to 25 minutes until the zucchini is tender and the cheese has melted into a beautiful golden crust.
Finish with a garnish of chopped fresh parsley before serving warm.