Preheat oven to 230C. Line a baking sheet with foil and coat foil generously with olive oil.
Toss eggplant slices with salt to taste and 2 tablespoons of the olive oil. Line baking sheet with the slices in a single layer (you may need 2 baking sheets, or do this in batches). Place in oven and roast for 15 minutes. Eggplant will look dry on the surface but should be soft when pierced with a knife. Remove from oven and, wearing oven mitts, carefully fold the foil up in half over the eggplant and crimp edges to create a sealed packet. Allow eggplant to steam inside the packet for another 15 minutes (you can cook couscous during this time). Turn oven down to 190 degrees.
Oil a gratin or baking dish with olive oil. Place cooked Israeli couscous in a bowl and stir in 1/2 cup of the tomato sauce. Spoon into a baking dish in an even layer.
Remove eggplant slices from foil packet (they should be thoroughly tender) and layer on top of couscous, overlapping slices slightly. Cover with remaining tomato sauce and sprinkle on Parmesan cheese. Drizzle on remaining tablespoon of olive oil. Place in oven and bake 30 minutes, until browned and bubbling. Allow to sit for at least 10 minutes before serving. Sprinkle with torn or slivered basil leaves.
And voila! Serve and enjoy with friends or family.