Wash the zucchinis and slice them in half lengthwise. Scoop out the flesh carefully using a spoon, leaving about 1/4-inch thick walls to create little “boats”. Set the zucchini halves aside.
Chop the scooped-out zucchini flesh and set it aside for the stuffing.
2. Make the Stuffing:
Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the chopped onion and garlic. Sauté for 3-4 minutes until softened and fragrant.
Add the ground turkey or beef to the skillet, breaking it apart with a spoon. Cook until browned, about 5-7 minutes.
Stir in the chopped zucchini flesh, diced tomatoes, oregano, basil, and red pepper flakes (if using). Season with salt and pepper to taste. Cook for another 5-7 minutes, until the zucchini softens and releases its moisture.
Stir in the cooked rice and half of the grated mozzarella cheese. Mix well, making sure everything is evenly combined. Taste and adjust seasoning as needed.
3. Stuff the Zucchini:
Spoon the stuffing mixture into each zucchini boat, packing it in tightly. Top with the remaining mozzarella cheese.
Optionally, sprinkle breadcrumbs on top of the stuffed zucchinis for an extra crispy topping.
4. Bake:
Place the stuffed zucchinis in a baking dish. Cover with foil and bake in the preheated oven for about 25 minutes.
After 25 minutes, remove the foil and bake for an additional 10-15 minutes, until the cheese is melted and bubbly, and the zucchinis are tender.