Instructions

1. Wash the eggplant and trim off the green stem. Cut it into slices 3-5 mm (1/8 to 3/16 inch) thick.
   
2. Layer the eggplant slices in a large colander, sprinkling each layer with coarse salt.
   
3. Cover the top layer with a flat plate and weigh it down with something heavy, such as a pot of water. Set the colander over a plate and let the eggplants rest for at least a couple of hours (or overnight).
   
4. Meanwhile, prepare the tomato sauce. In a saucepan, heat a bit of oil and sauté the peeled garlic clove.
   
5. (Optional) Peel and finely chop the onion. Add the onion to the saucepan and cook over low heat, stirring often, until it becomes translucent.
   
6. Pour the tomato passata into the pan, add salt, sugar, and stir. Bring to a boil, then simmer over low heat for about an hour, stirring occasionally. When the sauce is ready (it shouldn’t be too liquid), turn off the heat and add a few fresh basil leaves.
   
7. While the sauce is cooking, cut the mozzarella into small pieces and place them on a clean kitchen towel for at least half an hour to drain any excess moisture.
   
8. Meanwhile, rinse the eggplant slices under running water and pat them dry with a clean kitchen towel. Fry each slice in oil, or for a lighter option, brush them lightly with oil and bake in a preheated oven at 180°C/350°F for 10 minutes (at 160°C/320°F for 8-9 minutes in a ventilated oven) on each side.
   
9. Spread a bit of tomato sauce on the bottom of a baking dish.
   
10. Add a layer of eggplant slices, cover with tomato sauce, add some mozzarella, and sprinkle with grated cheese. Repeat until all ingredients are used.
    
11. Cover the top layer generously with cheese.
    
12. Bake the parmigiana in a preheated oven at 180°C/350°F for 40 minutes (at 160°C/320°F for 35-40 minutes in a ventilated oven). Let it cool slightly before serving.