Beat the eggs in a bowl. Mix the flour, salt, pepper, and oregano in a 1 gallon resealable plastic bag. Dip each eggplant slice in the egg, then drop the eggplant in the flour mixture one at a time, shaking the bag to coat the eggplant.
Heat the vegetable oil in a large, deep skillet over medium heat. Place the eggplant slices in the skillet to cook, turning occasionally, until evenly browned. Drain the eggplant slices on a paper towel-lined plate. Arrange the eggplant in one layer on a baking sheet. Spoon enough pizza sauce to cover each eggplant slice. Top each eggplant with mozzarella cheese.
Bake in the preheated oven until the mozzarella cheese is melted, 5 to 10 minutes.
