Halve the eggplants and blanch them in salted water for 10 minutes. Remove and drain well.
Heat the olive oil in a saucepan over medium heat. Add the onions and garlic, cooking for 3-4 minutes until translucent. Add the ham and cook for 1 minute. Pass the tomatoes through a sieve into the pan and simmer for 8-10 minutes until the sauce thickens. Remove from heat and stir in the breadcrumbs.
Mix the parsley into the mixture and season with salt and pepper.
Spoon the mixture into the eggplant halves, sprinkle the parmesan cheese on top, and bake at 190°C (375°F) for 20 minutes until the cheese is golden and the filling is heated through.