Preheat the oven to 400°F (205°C) and line a baking sheet with parchment paper.
Halve the zucchini lengthwise. With a spoon carefully scoop out the middle flesh from the center of each zucchini half. Discard the flesh. Set the zucchini aside.
Heat the oil in a large skillet over medium heat. Add the onion and cook for about five minutes or until tender.
Add the meat, stirring until well browned and crumbled, about 7-10 minutes.
Add the Italian seasoning and the crushed tomatoes. Continue cooking, stirring frequently, for about three minutes. Add salt and pepper to taste.
Place the zucchini halves cut side up on the baking sheet. Stuff the cavity of each with an equal portion of the filling and top with the mozzarella cheese.
Bake in the oven for 23 to 25 minutes or until the cheese is golden and the zucchini halves have softened. Divide between plates and enjoy!
