Turn the oven on to 425 degrees Fahrenheit.
In a large sheet pan, combine the eggplant, bell peppers, onions, and garlic with olive oil, salt, and pepper. Using a spatula, turn once during roasting to ensure even browning.
During this time, boil the orzo in salted water until tender, about 7 to 9 minutes.
Drain and place in a large serving bowl. Using a large spoon, scrape all the liquid and seasoning from the roasting pan into the pasta bowl, then add the roasted vegetables.
Add salt, pepper, olive oil, lemon juice, and lemon juice to the dressing and pour it over the pasta and vegetables. Stir in the scallions, pignolis, feta, and basil when the mixture has cooled to room temperature. Make sure the seasonings are right and serve at room temperature.