Place eggplant cubes in a shallow baking pan; toss with one third cup olive oil, sprinkle with salt to taste, and bake at 400 deg until cubes are soft but still hold their shape, about 30 minutes. Set aside to cool. Heat quarter cup olive ol in a large heavy frying pan; add onions and sweet peppers and cook over very low heat until vegetables are quite tender and slightly caramellized, about 35 to 45 minutes. Stir in garlic and salt and pepper to taste. Cook 5 minutes longer. Combine the remaining olive oil, lemon juice, Italian spices, and salt and pepper to taste. Whisk and reserve. Cook pasta in 4 litre boiling water until al dente. Drain and rinse well in cold water, then drain again. With a sharp knife, diagonally slice each piece of pasta in half crosswise. Toss in a large bowl with onion mixture and reserve dressing. Toss eggplant cubes and chopped basil with pasta. Garnish with basil leaves. Serves 6 to 8 as a first course, 10 to dozen as a salad. Good side dish with barbecued tofu.