Active time: 25 min Start to finish: 1 1/4 hr
Gratin can be assembled (but not broiled) 1 hour ahead and kept at room temperature.
Recipe information
Yield
Makes 6 servings
Ingredients
Special Equipment
Preparation
Step 1
Put oven rack in middle position and preheat oven to 425°F.
Step 2
Brush a shallow baking pan (1/2 to 1 inch deep) with 2 tablespoons oil. Arrange tomato slices in 1 layer in baking pan and sprinkle with a scant 1/2 teaspoon salt and 1/4 teaspoon pepper. Roast tomatoes until just tender (not falling apart), about 20 minutes.
Step 3
While tomatoes roast, cut potatoes crosswise into 1/4-inch-thick slices and toss with 5 tablespoons oil in a large bowl.
Step 4
Remove tomatoes from oven and put oven racks in upper and lower thirds of oven. Arrange potato slices in 1 layer in 2 shallow baking pans (1/2 to 1 inch deep) and sprinkle each pan with a scant 1/2 teaspoon salt and 1/4 teaspoon pepper. Roast potatoes, switching position of pans halfway through roasting, until tender, about 16 minutes total.
Step 5
While potatoes roast, mince garlic and mash to a paste with a pinch of salt using a large heavy knife. Transfer paste to a bowl and stir in bread crumbs, basil, thyme, remaining 3 tablespoons oil, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon pepper.
Step 6
Preheat broiler.
Step 7
Arrange tomatoes and potatoes in 1 layer in gratin dish, alternating slices and overlapping them, and spoon any juices from tomatoes into dish. Sprinkle top with bread crumbs and broil 5 to 7 inches from heat, checking frequently after 1 minute (crumbs can brown quickly), until golden brown, about 2 minutes. Serve warm or at room temperature.
