Summer Vegetable Gratin

I've mentioned my new cooking bible before.

I've had this recipe kicking around since August. Sara raved about it. I finally got around to making it for a dinner with J's sister last weekend.

Like all ATK recipes, it's labor and time intensive, but oh-so-worth-it.

Next year's garden will be exclusively zucchini, yellow squash and tomatoes, so I can make this once a week. At least.

SUMMER VEGETABLE GRATIN
Adapted from America's Test Kitchen Summer Vegetable Gratin.
Click the link for all the details. Here I will just sum up.

Serves 6-8 as a side, or 4 as a main dish.

6 TB olive oil (or canola oil...I prefer canola)
1 lb. zucchini (about 3), ends trimmed and sliced crosswise into 1/4-inch-thick slices
1 lb. yellow squash (about 3), ends trimmed and sliced crosswise into 1/4-inch-thick slices
2 tsp table salt
1 1/2 pounds ripe tomatoes (3 large or 5 medium), sliced 1/4 inch thick
2 medium onions , halved and sliced thin (about 3 cups)
3/4 tsp pepper
2 medium garlic cloves (about 2 tsp), minced
1 TB minced fresh thyme (or 1/2 TB dried thyme)
1 large slice of bread
1 cup grated Parmesan cheese

Toss zucchini and yellow squash slices with 1 tsp salt in large bowl; transfer to a colander set over a bowl. Let stand until zucchini and squash release at least 3 TB of liquid, about 45 minutes. Arrange slices on triple layer paper towels; cover with another triple layer paper towels and firmly press each slice to remove as much liquid as possible.

Place tomato slices in single layer on double layer paper towels and sprinkle evenly with 1/2 tsp salt; let stand 30 minutes. Place second double layer paper towels on top of tomatoes and press firmly to dry tomatoes.

Heat 1 TB oil in medium skillet over medium heat. Add onions, 1/2 tsp salt, and 1/4 tsp pepper; cook, stirring occasionally, until onions are softened and dark golden brown, 20 to 25 minutes. Set onions aside.

Combine garlic, 3 TB oil, 1/2 tsp pepper, and thyme in small bowl.

Adjust oven rack to upper-middle position and heat oven to 400 degrees. Brush 13- by 9-inch baking dish with 1 TB oil.

In large bowl, toss zucchini and summer squash in half of oil mixture, then arrange in greased baking dish.

Layer caramelized onions over squash.

Slightly overlap tomato slices in single layer on top of onions.

Spoon remaining garlic-oil mixture evenly over tomatoes.
Bake at 400 degrees for 40-45 minutes, until vegetables are tender and tomatoes are starting to brown around the edges.

While veggies are baking, process bread in food processor about 10 seconds. (You should have about 1 cup crumbs.) Combine bread crumbs, 1 TB oil and Parmesan.

Remove baking dish from oven and increase to 450 degrees. Sprinkle bread crumb mixture evenly on top of tomatoes. Bake 5-10 minutes, until gratin is bubbling and cheese is lightly browned. Let rest 10 minutes before serving.