Prep the Zucchini– Preheat oven to 400°F (200°C). Wash and dry 5 zucchini, slice in half lengthwise, and scoop out the flesh with a spoon or melon baller. Finely chop the scooped-out flesh and set aside.
Cook the Filling – In a large skillet, heat 1 tablespoon olive oil over medium heat. Add 3 spring onions (chopped) and 3 cloves garlic (grated); sauté for 2–3 minutes. Stir in the chopped zucchini flesh, 1 teaspoon dried oregano, 1 teaspoon salt, and ⅛ teaspoon black pepper. Cook about 5 minutes until the moisture evaporates.
Mix the filling– Transfer mixture to a bowl. Stir in 1 cup ricotta cheese, ¾ cup parmesan cheese, ½ packed cup sun-dried tomatoes (chopped), ½ cup breadcrumbs, and 1 teaspoon grated lemon zest. Mix until well combined.
Assemble and Bake – Fill zucchini boats with the stuffing and place on a parchment-lined baking sheet. Top with extra parmesan or mozzarella if desired. Bake for 20 minutes (or air-fry at 350°F / 180°C for 12–15 minutes) until golden on top and tender-crisp. Serve warm with a squeeze of lemon juice and fresh basil, if you like.