Eggplant parmigiana (parmigiana di melanzane)

2 large (1kg) eggplants coarse cooking salt
1/2 cu (125ml) olive oil
2 tablespoons olive oil, extra
1 medium (150g) onion, finely chopped
2 cloves garlic, crushed
2 * 425g cans tomatoes
2 tablespoons tomato paste
1 teaspoon sugar
1/4 cup shredded fresh basil
400gmozzarella cheese, thinly sliced
1/3 cup (25g) grated parmesan cheese
Preparation :
1. Cut eggplants into 1 cm slices , place on wire racks over oven trays , sprinkle with salt ; stand 30 minutes. Rinse under cold water , drain on absorbent paper .
2. Place eggplant slices in single layer on lightly greased oven trays . Brush with oil .grill on both sides until lightly browned ; drain on absorbent paper.
3. Heat extra oil in pan, add onion and garlic , cook , stirning, until onion is soft. Add undrained crushed tomatoes. paste and sugar , simmer , uncovered , about 10 minutes or until mixture is thickened slightly Stir in basil.
4. Grease shallow ovenproof dish (2 litre / 8 cup capacity) . Pour half the tomato mixture into dish , top with half the eggplant slices , then half  the mozzarella slices ; sprinkle with parmesan. Repeat with remaining tomato mixture , eggplant slices , mozzarella slices and parmesan.Bake , uncovered , in moderately hot oven about 40 minutes or until cheese is melted .
Serves 6.
* Recipe can be made a day ahead.
* Storage: Covered , in refrigerator.
* Freeze: Suitable.
* Microwave: Not suitable.