Potato-Tomato Gratin

Directions

1. 1
   {"0":"1. Adjust oven rack to upper-middle position and heat oven to 400 degrees. Grease 13 by 9-inch baking dish. Heat oil in 12-inch skillet over medium heat until shimmering. Add onions, 1\/2 teaspoon salt, and 1\/4 teaspoon pepper and cook, stirring frequently, until soft and golden brown, 15 to 20 minutes.","2":"2. Add garlic and cook until fragrant, about 30 seconds. Add water and cook until nearly evaporated, scraping up any browned bits, about 2 minutes. Off heat, stir in olives; set aside.","4":"3. Shingle half of tomatoes in even layer in prepared dish. -Shingle half of potatoes over tomatoes and sprinkle 1 teaspoon thyme, 1\/2 teaspoon salt, and 1\/4 teaspoon pepper over top. Spread onion mixture evenly over potatoes. Shingle remaining potatoes over onions. Shingle remaining tomatoes over potatoes. Sprinkle remaining 1 teaspoon thyme, 1\/2 teaspoon salt, and 1\/4 teaspoon pepper over top.","6":"4. Bake, uncovered, for 1 hour. Sprinkle with Gruyere and continue to bake until cheese is browned and bubbly and potatoes are completely tender, 25 to 30 minutes longer. Let cool for 30 minutes. Serve.","8":"Gratins are layered practically by definition. For our Potato-Tomato Gratin, in which the potato slices gently cook in the juices released by the tomatoes, it's critical that each potato layer adjoin a tomato layer.","12":"LAYERS FROM TOP TO BOTTOM","14":"cheese","15":"tomato","16":"potato","17":"onion","18":"potato","19":"tomato"}