Vegetable Tian

Ingredients

• 1/3 to 1/2 cup olive oil
• 1 small eggplant (about 6 ounces), thinly sliced crosswise on a slight diagonal
• 1 yellow squash or zucchini (about 6 ounces), thinly sliced crosswise on a diagonal
• 4 plum tomatoes (about 1 pound), sliced lengthwise 1/4 inch thick
• 2 small red, white, or yellow onions (8 ounces), thinly sliced crosswise
• Coarse salt and freshly ground pepper
• Sprigs of herbs, such as thyme, rosemary, oregano, or marjoram
• 1 head garlic, separated into cloves but not peeled