Zucchini, Tomato, and Potato Tian with Caramelized Onions
Serves 6. Published December 1, 2007. From ATK Books.
Try to buy squash and tomatoes that have roughly the same diameter. Slicing the vegetables 1/4 inch thick is crucial for the success of this dish; use a mandoline, a V-slicer (see related content), or a food processor fitted with a 1/8-inch-thick slicing blade. You can also slice them carefully by hand using a very sharp knife. An ovensafe Provençal-style gratin dish can be substituted for the 13 by 9-inch baking dish, as long as it’s of similar size.
2 tablespoons extra virgin olive oil
3 slices thick-cut bacon , sliced into thin strips
3 medium yellow onions , halved and sliced 1/4 inch thick (about 3 cups)
2 medium garlic cloves , minced or pressed through a garlic press (about 2 teaspoons)
1 pound zucchini , trimmed and sliced 1/4 inch thick
1 pound russet potatoes , peeled and sliced 1/4 inch thick
1 pound plum tomatoes , cored and sliced 1/4 inch thick
1 teaspoon minced fresh thyme leaves
Ground black pepper
2 ounces shredded Gruyère cheese (about 1/2 cup)
1. Adjust an oven rack to the middle position and heat the oven to 375 degrees. Brush a 13 by 9-inch baking dish with 1 tablespoon of the oil; set aside.
2. Cook the bacon over medium heat until the fat has rendered, about 5 minutes. Add the onions and 1/2 teaspoon salt and cook until softened and lightly browned, 12 to 15 minutes. Stir in the garlic and cook until fragrant, about 30 seconds. Spread the onion mixture onto the bottom of the prepared baking dish.
3. Following the illustration below, alternately shingle the sliced zucchini, potatoes, and tomatoes into a single layer of 4 tightly fit rows on top of the onions. Sprinkle with the remaining 1 tablespoon oil and thyme and season with salt and pepper. Cover the dish with aluminum foil and bake until the vegetables are tender, about 30 minutes.
4. Remove the foil, sprinkle the cheese over the top, and continue to bake until bubbling around the edge and lightly browned on top, 20 to 30 minutes. Let rest for 10 minutes before serving.
Making a Vegetable Tian