Preheat oven to 375°.
Cut eggplants in half lengthwise. Using a spoon, hollow out eggplants, leaving about a 1/2-inch-thick border around skin.
Place the four eggplant halves, flesh-side up, onto a greased baking sheet (or into a big casserole dish) and use your fingers or a food brush to smear about 2 Tbsp. of oil over the flesh side of the cut eggplant. Season with pepper and a little salt and place into the oven to roast until tender and easily pierced with a paring knife, about 30 minutes.
While the eggplant is roasting, prepare your filling: Heat olive oil in a large skillet over medium high heat. Roughly chop eggplant centers, and add to pan together with onion, garlic, oregano, and pepper. Cook and stir until lightly browned.
Add the tomatoes or tomato sauce and remove from heat.
Add breadcrumbs and ½ cup cheese and stir to combine. Taste for seasoning.
Fill each roasted eggplant half with equal portions of the filling. Top with the remaining cheese.
Bake in the preheated oven for another 10 minutes, or until the cheese is melted and bubbly.
