Preheat the oven to 400°F.
Slice eggplants lengthwise evenly.
Scoop flesh gently, leaving thick shells.
Chop the scooped flesh finely.
Brush shells with olive oil lightly.
Place shells on a baking sheet.
Heat oil in a skillet.
Sauté onion until soft.
Add garlic and cook briefly.
Stir in chopped eggplant flesh.
Cook until tender and fragrant.
Add tomatoes and cook gently.
Remove skillet from heat.
Mix breadcrumbs, herbs, and Parmesan.
Season the filling well.
Spoon filling into eggplant shells.
Top with mozzarella cheese evenly.
Bake until golden and bubbling.