Relax and enjoy prepping this delicious gratin. It takes a bit of time, but it’s satisfying time, especially when it comes to assembling the rows of veggies. And once the gratin is in the oven, you’ve got the star of dinner made – whether you put it at the center of the plate or on the side.

Be sure you have a shallow 2-quart baking dish for this. I love enameled cast-iron gratin dishes with sloped sides (made by Le Creuset, Staub, and Lodge), but a Pyrex rectangular 2-quart baking dish will work fine too.

Susie Middleton

Serves 6 as a side dish

For the eggplant:

  • 2 pounds Italian (or small globe) eggplant, ends trimmed, cut into slices about 3/8-inch thick
  • 1/3 cup (or more) olive oil
  • Kosher salt

For the leeks:

  • 1 tablespoon olive oil
  • 1 tablespoon unsalted butter
  • 2 cups thinly sliced leeks (2 to 3 large leeks, white and light green part only) 
  • Kosher salt
  • 2 cloves garlic, finely chopped

To assemble the gratin:

  • 1/3 cup fresh breadcrumbs
  • 1/3 cup coarsely chopped toasted almonds
  • Olive oil
  • Kosher salt
  • 1/3 cup thinly sliced or coarsely chopped fresh mint (or combine mint with oregano, cilantro, basil, or parsley) 
  • 2 teaspoons balsamic vinegar
  • 1½ pounds ripe plum tomatoes, cored and cut into 1/4-inch slices, ends discarded
  • 6 ounces (about 1¼ cups) crumbled feta (keep chilled after crumbling)

To roast the eggplant:
1. Heat the oven to 450 degrees. Line two baking sheets with parchment paper. Arrange the eggplant slices in one layer on the parchment. Brush the tops of the slices with half of the olive oil, season with salt, flip the slices, and brush the other sides with the remaining oil. Season again.

Susie Middleton

2. Roast until the slices are lightly browned and somewhat shrunken, about 25 minutes. Rotate the pans back to front and from rack to rack halfway through cooking. Reduce the oven temperature to 375 degrees.

To prepare the leeks: 
1. Put the sliced leeks in a bowl of tepid water for a few minutes, which will help them release dirt.

2. In a medium nonstick skillet, heat the olive oil and butter over medium heat. (Nonstick is important here; leeks release a sticky substance when cooked.) With your hands, lift the leeks out of the water and put them in the skillet. (This will leave the dirt behind in the bottom of the bowl.) It’s okay that there is some water still clinging to the leeks; it will help start the cooking.

3. Sauté, stirring frequently, until the leeks have softened, shrunk in volume, and are just beginning to turn brown, about 15 minutes. Reduce the heat to medium-low if they’re browning too quickly. Add the garlic and sauté until soft and fragrant, 1 to 2 minutes. Remove the skillet from the heat.

To assemble the gratin:
1. In a small bowl, combine the breadcrumbs, the chopped nuts, 1 teaspoon olive oil, a pinch of salt, and 1 tablespoon of the herbs.

2. In another small bowl, combine 1 tablespoon olive oil, the balsamic vinegar, and a pinch of salt. Whisk together.

3. Lightly oil a 2-quart shallow baking dish. Transfer the leeks and garlic from the skillet (scraping out any brown stuff on the bottom of the skillet) to the baking dish and spread evenly to cover the bottom of the dish.

4. Sprinkle 1 tablespoon of the herbs over the leeks. Starting at one end of the baking dish, lay a row of slightly overlapping tomato slices across the width of the dish; sprinkle with a pinch of salt, some of the herbs, and some of the feta. Next, lay a row of eggplant slices against the tomatoes (overlapping the first row by two-thirds). Sprinkle again with herbs and feta. Repeat with alternating rows of tomato and eggplant slices, seasoning each as you go, and occasionally push the rows back a bit so you can fit as many rows in as possible.

5. When the gratin is full, sprinkle the vegetables with about a ½ teaspoon of salt and any remaining herbs and feta. (You will probably have a few extra eggplant and tomato slices.) Drizzle with the olive oil–balsamic mixture; then cover with the breadcrumb and nut mixture. Cook until well-browned all over and the juices have bubbled for a while and reduced considerably, 50 to 60 minutes. Let cool for at least 15 minutes before serving. The gratin is better warm than piping hot.