If you want a beautiful side dish to set on the table, this tomato and eggplant gratin is it. Especially when made with colorful heirloom tomatoes. It tastes rich and decadent but is actually quite healthy when you take into account the antioxidants  from the tomatoes and eggplant, potential health benefits of full fat dairy  and protein from eggs.
Did you know that eggplant  has high levels potent antioxidants? And as most people know, so do tomatoes. Healthwise and flavorwise they make a good team. But enough about all the healthy stuff. Plain and simple, this tomato and eggplant gratin is delicious. Really, delicious. Make it in the summer with perfectly ripe heirloom tomatoes or make it in the winter and serve it as a holiday side dish.
Time in the Kitchen: 2 hours
- 2 eggplants, peeled (optional) and sliced into rounds 1/4-inch thick (6 mm)
- 2 tablespoons (30 ml) plus 1/2 teaspoon (2.5 ml) kosher salt, divided
- 2 pounds tomatoes, thinly sliced (900 g)
- 1/2 cup olive oil (120 ml)
- 2 eggs
- 1 cup heavy cream (240 ml)
- 1/4 cup finely chopped parsley (60 ml)
Preheat an oven to 375 °F/190 °C.
In a large bowl, dissolve 2 tablespoons (30 ml) salt in 1 cup (240 ml) warm water. Once the salt is dissolved, put the eggplant slices in the salt water. Add enough cool water to cover the eggplant, 4 to 6 cups. (950 ml to 1420 ml) .Set a plate that is slightly smaller than the top of the bowl on the eggplant pieces to keep them submerged in the water. Let sit for 30 minutes. (Brining eggplant removes bitterness and keeps the texture from turning dry and leathery when roasted or grilled.)
While the eggplant is soaking, place the tomato slices on a baking sheet lined with parchment paper (to prevent sticking) and drizzle lightly with olive oil. Roast for 20 to 25 minutes. The tomatoes should release most of their moisture and become soft and shriveled. Take the tomatoes out, let cool, and set aside.
Drain the eggplant and pat thoroughly dry.
Lay the eggplant slices out evenly on baking sheets and lightly brush with olive oil on both sides. You’ll probably use around 1/2 cup of olive oil to do this. Roast until the eggplant is soft, 30 minutes.
In a large oval (or 9×13 cake pan) layer the eggplant and tomato .
Whisk together eggs, cream, parsley and remaining 1/2 teaspoon salt.
Pour the custard on top of the tomato and eggplant.
Bake 30 to 35 minutes until the custard is set and lightly browned.