Eggplant, Zucchini, and Tomato Gratin

This vegetable gratin is an excellent accompaniment for grilled lamb chops or roast leg of lamb, or broiled or roasted chicken. It also makes a very nice lunch accompanied with some good bread and a small salad. Don’t overload it with cheese—it should be light in texture. And don’t worry about leftovers; the gratin is delicious reheated.