Preheat oven to 375 degrees F (190 degrees C). Grease a baking sheet or pizza pan with olive oil.
Slice the eggplant into 8 round slices, each 1/4 to 1/2 inch thick. Trim the skin, maintaining the round shape of the slices. In a small bowl, whip together the egg and water. Place the breadcrumbs in a separate small bowl.
Dip the eggplant slices one at a time into the egg and water mixture, then into the breadcrumbs. One by one, place the coated slices in a single layer on the prepared baking sheet or pizza pan. Top the slices with equal amounts of tomato, Parmesan cheese and Italian-style salad dressing.
Bake in the preheated oven approximately 15 minutes. Change oven setting to broil, and continue cooking 3 to 5 minutes. Check the slices frequently while broiling to avoid burning.