Method:

Prepare the Zucchini: Preheat your oven to 350°F (175°C). Wash the zucchinis, cut off the ends, and slice them into 2-inch pieces. Using a melon baller or spoon, carefully hollow out the centers of each piece, leaving enough flesh at the bottom to form a cup.

Cook the Filling: In a frying pan, heat 1 tablespoon of olive oil over medium heat. Add the diced onion and the zucchini flesh you scooped out. Cook for 8 minutes, stirring occasionally, until the mixture is golden brown. Set it aside to cool.

Fry the Zucchini Shells: In a separate pan, heat the remaining olive oil and fry the zucchini shells for 6-8 minutes until lightly golden. Set them aside on a paper towel to drain excess oil.

Prepare the Stuffing: Once the zucchini mixture is cool, combine it in a bowl with the egg, breadcrumbs, and Parmigiano. Season with salt and pepper. Stir well to combine.

Stuff the Zucchini: Drizzle a bit of olive oil in your baking dish. Place the zucchini shells in the dish and stuff them with the mixture, packing it down lightly. Sprinkle the tops with extra breadcrumbs and Parmesan, and drizzle with a little more olive oil.

Bake: Place the dish in the oven and bake for 35-40 minutes, or until the tops are golden brown and crispy.

Variations:

Add Meat: For a non-vegetarian version, you can add ground beef or sausage to the stuffing.

Vegan: Use a flax egg (1 tablespoon ground flaxseed + 2 tablespoons water) and swap out the Parmesan for a dairy-free cheese.

Herbs: Try adding fresh basil, parsley, or oregano to the stuffing for extra flavor.

Tips & Substitutions:

Zucchini Size: Larger zucchinis tend to hold up better to stuffing, but if you can only find smaller ones, consider using multiple zucchinis or slicing them lengthwise to create more "boats."

Breadcrumbs: You can use gluten-free breadcrumbs if needed, or even substitute crushed crackers or nuts for added texture.