Grind onion and tomato into a fine paste
Heat Olive oil in a pan
Sauté eggplant well until tender, keep aside
Add garlic sauté well
Add tomato onion puree and and cook well until it becomes thick paste
Remove from the heat and stir in the grated cheese and add pepper
Mix this with cooked penne
Plate up the pasta and serve with the eggplant and little olive oil on top