This tian (a Provencal gratin) has a lovely base of sautéed onions and bell peppers hiding beneath rows of tomatoes and summer squash. (Sometimes I skip the peppers; sometimes I use leeks instead of onions!) Cook the gratin long enough to reduce the juices; you will know the gratin is done when the edges of the gratin are deeply browned . Let cool a bit before serving; leftovers are delicious.

This recipe is a hybrid of two tians I did for my cookbooks, Fresh From the Farm, and The Fresh and Green Table (Chronicle books). I love to use an enameled cast iron gratin dish for this; sometimes I use a few mini baking dishes instead of one large one, but they are always shallow. You want the rows of ingredients overlapping but not piled on top of each other! Also keep in mind that depending on how you do the arranging and your pan, you may have a few extra slices of vegetables. 

Susie Middleton

Serves 4

  • 5 tablespoons plus 2 teaspoons extra-virgin olive oil, more for the pan
  • 3/4 cup fresh bread crumbs
  • 3/4 cup coarsely grated Parmigiano-Regianno
  • 1 tablespoon chopped fresh thyme
  • 2 teaspoons balsamic vinegar
  • 2 teaspoons honey
  • 3/4 pound (12 ounces, about 1 1/2 small) zucchini or other summer squash, sliced thinly on the diagonal (about 1/8 to 3/16 inch thick)
  • 1 1/4 pound small to medium red and/or orange ripe tomatoes (about 4 or 5), cored, sliced about 3/16-inch thick (cut medium tomatoes in half first, then slice)
  • Kosher salt
  • 2 small onions (about 8 ounces total), thinly sliced (about 1 3/4 cups)
  • 1 small or 1/2 large red or yellow bell pepper (about 4 ounces), cored and very thinly sliced
  • 2 teaspooons minced fresh garlic
  • 3 tablespoons finely chopped oil-packed sundried tomatoes (drained), optional


1. Preheat the oven to 375 degrees F. Rub a shallow 2-quart baking dish with a little olive oil. In a small bowl, combine the bread crumbs, 2 tablespoons of the Parmigiano, 1/2 teaspoon of the thyme, and 2 teaspoons of the olive oil. Mix well.

2. Whisk together the balsamic vinegar, the honey, 2 tablespoons of olive oil, and 1/4 teaspoon salt. Put the squash slices in one bowl and the tomato slices in another. Add a pinch of salt and 1 teaspooon thyme to each bowl, and drizzle half of the balsamic mixture over each. Toss gently. Let sit while you prepare the rest of the recipe.

3. In a medium (10-inch) heavy nonstick skillet, heat 1 tablespoon of the olive oil over medium heat. Add the onions, the peppers, and 1/4 teaspoon salt. Cook, stirring frequently, until the peppers are limp and the onions are golden brown, about 10 to 12 minutes. Stir in the minced garlic and cook until softened, about 30 seconds. Transfer the onions and peppers to the baking dish and spread them evenly in one layer across the bottom. Let cool slightly. Sprinkle the sundried tomatoes and the remaining 1/2 teaspoon of the thyme over the veggies.

4. Starting at one end of the baking dish, arrange a row of tomato slices, slightly overlapping each other, propped up against the end of the dish at a bit of an angle. Sprinkle a little Parmigiano over the row of tomatoes, and then arrange a row of zucchini slices, slightly overlapping each other and slightly overlapping the row of tomatoes. Again sprinkle Parmigiano on that row, and continue to arrange rows of tomatoes and zucchini, each sprinkled with Parmigiano, until you get to the end of the dish. You should have just about the right amount of zucchini, but don’t worry if you have extra slices. You will definitely have extra tomato slices (some will have fallen apart!), but as you are going along, if it looks like you will have a lot of extra, gently push the rows back up towards the end of the dish to make room for a few more rows.

5. Scrape any remaining seasoning and juices from the bowls over the veggies. Sprinkle any remaining Parmigiano over the veggies and drizzle with the remaining 2 tablespoons of olive oil. Top with the bread crumb mixture.

6. Bake until well browned all over and the juices have bubbled for a while and reduced considerably, about 60 to 65 minutes. Let cool at least 15 minutes before serving.