For the eggplant, preheat the oven to 450 degrees F and line a baking sheet with parchment paper.
Place the eggplant on the pan and make 3 to 4 small slashes in each eggplant with a knife. Brush each eggplant with some olive oil and sprinkle it with a dash of salt and a dash of pepper.
Bake the eggplant for 25 minutes, or until it’s soft when pierced with a knife. Remove from oven.
Reduce the oven temperature to 350 degrees F.
Slice the top third of the eggplant lengthwise. Scoop out flesh from the inside of both pieces. The bottom part of the eggplant skin that is left (that resembles a boat) is the part you will stuff. Discard the extra skin from the top third.
For the filling, heat the oil in a skillet over medium heat, add the onions, and saute them for 5 minutes, until softened.
Add the beef and cook it for 10 minutes, crumbling it as you cook, until it’s evenly browned.
Add the wine and stir it in well. Stir in the garlic, diced tomatoes, oregano, and eggplant flesh, and cook the mixture, uncovered, for 5 minutes.
Stir in the lemon juice, salt, pepper, and parsley.
Spoon the stuffing into the eggplant shells on the baking dish and top it with the parmesan cheese. Bake the stuffed eggplant for 25 minutes, until the cheese is melted and lightly browned.