• Preheat oven to 350 degrees F and grease a baking sheet.
• Begin by cutting the eggplant in half, lengthwise, and hollowing them. I use a knife to score the flesh of the eggplant and then a spoon to scoop out the flesh. Set aside the flesh in a bowl.
• Drizzle olive oil over the hollowed baby eggplant, salt lightly and bake in a 350 degrees F preheated oven for 15 minutes.

Prepare the filling

• Heat olive oil in a large skillet and sauté a small finely diced onion.  Add garlic, the reserved eggplant flesh roughly chopped and cook until tender, stirring occasionally, for 5-7 minutes.
• Pour in tomato passata or finely diced fresh tomato and cook 5 minutes longer. Season with salt and pepper, to taste.
• Transfer the eggplant mixture to a large bowl and let cool slightly.  Add fresh breadcrumbs, torn into small pieces, from day old bread; grated Pecorino Romano cheese; cubed mozzarella; chopped parsley; and egg. Combine well.

Stuff and bake

• Fill the baked eggplant shells, sprinkle extra grated Pecorino Romano cheese on each half and place on the prepared baking sheet. Bake for 25 minutes until golden brown. Serve hot or at room temperature.