Split the eggplants in half lengthwise. Run a sharp paring knife around the inside perimeter of each half, about 1inch from the skin. Do not penetrate the skin. Score the insides of each half with the paring knife, running it to within about ½inch of the bottom skin. The scoring should have a diamond pattern.
Sprinkle the tops of each half with salt. Place the halves, cut side up, in a baking dish and place in the oven. Bake about 25 minutes.
Heat the oil in a skillet and add the garlic and onions. Cook until the onions wilt, about 5 minutes. Add the beef, stirring and chopping down with the side of a heavy metal spoon to break up any lumps.
Add the tomatoes and cover. Continue cooking about 10 minutes. Uncover.
Meanwhile, bring about 4cups of water to the boil. Add the rice and cook, stirring occasionally, about 10 minutes. Drain.
When the eggplants are ready, remove from the oven. Using a spoon, scoop out the center scored portion, leaving the ½-inch-thick shell. Chop the center pulp. There should be about 1½cups.
Add the pulp to the beef mixture and continue cooking about 1 minute. Add the drained rice and stir. Add the lemon juice, parsley, and salt and pepper to taste.
Arrange the eggplant shells on a baking dish. Fill with the beef mixture, piling it up until all is used. Sprinkle the top of each eggplant half with 1tablespoon grated Parmesan cheese.
When ready to cook, preheat the oven to 375 degrees.
Place the dish in the oven and bake for 30 minutes.