Brush the eggplant with olive oil and sprinkle with oregano; salt and pepper to taste.
Place on a baking sheet in a single layer and place about 6-inches under a hot broiler. Broil on one side until brown and tender. (if brown before tender, you can flip them over, but it's not necessary). Repeat until all eggplant it browned.
Preheat oven to 400F.
Lightly grease a 13x9 casserole/baking dish with ollive oil.
Spread just enough tomatoes to cover the bottom of the pan lightly.
Add a single layer of eggplant, then top with a light layer of tomatoes.
Sprinkle with garlic, oregano, salt and pepper, mozzarella cheese and parmesan cheese (in that order). Continue layering until you end with parmesan cheese on top.
Cover and bake for about 30 minutes or until hot and bubbly.
OPTIONAL - Uncover and bake about 5 more minutes to brown cheese more if desired.
Serve immediately or allow to cool until room temperature before serving.