Put a large saute pan over a medium-high flame and heat the olive oil. Fry the egglplant slices in batches until slightly browned, about 2-3 minutes per batch. Transfer to a paper towel lined plate. Set aside.
In another large saute pan with a lid add about half the marinara sauce to the bottom. Add a layer of eggplant slices to the pan and spoon a bit of marinara sauce over each slice.
Top with a bit of mozzarella and a teaspoon of parmigiano cheese. Repeat twice more. Cover the pan and cook over low flame for 20-25 minutes.