serves 6-8 as a side, or 4 as a light entree (and can be halved quite easily)
Ingredients:
6 Tablespoons olive oil
1 pound zucchini, ends trimmed and sliced crosswise into 1/4-inch slices
1 pound yellow squash, ends trimmed and sliced crosswise into 1/4-inch slices
2 teaspoons salt
1 1/2 pounds ripe tomatoes (3-4 large), sliced 1/4-inch thick
2 medium onions, halved lengthwise and sliced thin (about 3 cups)
3/4 teaspoon ground black pepper
2 medium garlic cloves, minced
1 Tablespoon minced fresh thyme leaves
1 large slice good-quality white sandwich bread, torn into quarters
2 ounces grated Parmesan cheese (about 1 cup)
2 medium shallots, minced (1/4 cup)
1/4 cup chopped fresh basil leaves
Directions:
Adjust the oven rack to the upper-middle position and heat the oven to 400 degrees. Lightly oil a 9x13 inch baking dish and set aside.
Toss zucchini and squash slices with 1 teaspoon of salt in a large colander, and allow to drain about 45 minutes, or until they release 3 Tablespoons of liquid. Arrange slices on a triple layer of paper towels or a dish towel, cover with a clean dish towel, and press firmly to remove as much moisture as possible.
As the squash and zucchini drain, line another dish towel with the tomatoes, and sprinkle with 1/2 teaspoon salt. Allow to stand 30 minutes, then using a clean dish towel or paper towels, press firmly to dry the tomatoes.
Meanwhile, heat 1 Tablespoon of the oil in a 12-inch skillet over medium heat until shimmering. Add the onions, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Cook, stirring occasionally, until onions are softened and dark golden brown, about 20 minutes. Set aside.
Combine the garlic, 3 Tablespoons of oil, 1/2 teaspoon pepper, and thyme in a small bowl. Whisk to combine. In a large bowl, toss the squash and zucchini with half the garlic-oil mixture. Arrange in the baking dish, then top with an even layer of the onions. Slightly overlap the tomato slices in a single layer over the onions, and drizzle with the remaining oil mixture. Bake until the vegetables are softened and tomatoes are starting to brown around the edges, 40-45 minutes.
As the vegetables cook, pulse the bread in a food processor until finely ground (You should have about 1 cup of crumbs). Combine the bread crumbs, Parmesan, 1 Tablespoon oil, and shallots in a medium bowl.
Remove the baking dish from the oven and increase the heat to 450. Sprinkle the bread crumb mixture over the vegetables, and bake gratin until bubbling and lightly browned, 5-10 minutes. Remove from oven and sprinkle with basil. Allow to sit at room temperature 10 minutes before serving.
