Do not peel the eggplant. Slice off the green cap and cut the eggplant in half lengthwise. Use a sharp knife to score the meat into 1/2-inch cubes, leaving 1/2-inch rim around the edge. Scoop out the flesh with a spoon and coarsely chop it.
Heat the olive oil in a large skillet. Add the eggplant cubes and the onion to the skillet and saute over low heat, stirring frequently, until the eggplant is softened and lightly browned, about 8 to 10 minutes. Remove the pan from the heat and stir in the bread crubms, Parmesan cheese, eggs, and parsley. Season with the salt and black pepper.
Preheat the oven to 350 degrees (F).
Sprinkle the eggplant shells lightly with salt and pepper and divide the stuffing between them. [The recipe may be made ahead up to this point and wrapped and refrigerated for up to 3 hours.]
To make the Potato-Tomato Sauce, coat the bottom of a 7-by-11 inch baking dish with the 2 Tablespoons olive oil. Pour the can of tomatoes into the baking dish and cut them into quarters with a sharp knife or the side of a spoon. Add the water to the pan. Peel the potato and cut it into thin (no more than 1/4-inch thick) slices. Stack the slices, cut them into 1/4-inch strips, and cut the strips into small cubes. Add them to the tomato mixture in the baking dish, along with the garlic, oregano, salt, and pepper. Set the stuffed eggplant shells on top of the tomato mixture. Sprinkle the Parmesan cheese over the tops of the eggplant and into the sauce, and spoon a few pieces of tomato from the sauce onto the tops of the eggplant to help keep it moist. Drizzle a teaspoon or two of olive oil over the tops of the eggplant. 6. Bake, uncovered, in the preheated oven until the potatoes are tender and the tops of the eggplant are lightly browned, about 1 to 1-1/4 hours. The sauce will reduce quite a bit as it cooks. Cut each stuffed eggplant in half, and serve one piece each with some sauce spooned over it.
from Sunday Suppers, by Melanie Barnard & Brooke Dojny 1988 ISBN 0-13-875832-8