Provençal Vegetable Gratin (Tian)
A tian is a type of gratin, typically vegetables baked in an earthenware dish. (The word “tian” also refers to the earthenware dish itself.) This classic Provençal version is made with alternating rows of sliced zucchini, eggplant, and tomato. The flavors meld as the vegetables cook together, somewhat like ratatouille. Seasoned simply with thyme, garlic, and good fruity olive oil, the dish is best served at room temperature. Lulu insists it tastes even better made a day in advance.
- 6 tbsp. extra-virgin olive oil, plus more
- 2 large white or yellow onions, thinly sliced
- Kosher salt and freshly ground black pepper
- 2 tsp. chopped thyme
- 1⁄4 tsp. crushed chile flakes
- 6 cloves garlic, minced
- 1 lb. medium zucchini, cut into 1/4-inch-thick slices
- 1 1⁄2 lb. small, firm eggplant, cut into 1/4-inch-thick slices
- 1 1⁄2 lb. ripe tomatoes, cored and cut into 1/4-inch-thick slices
- Basil leaves, to garnish
- Put oil in a large skillet over medium-high heat. Add onions and season with salt and pepper. Cook until softened, about 5 minutes. Add thyme, chile flakes, and garlic. Cook 2 minutes more.
- Heat oven to 400°. Spread the cooked onion mixture in the bottom of a large earthenware baking dish, about 9 by 13 inches. Arrange the zucchini, eggplant, and tomatoes in alternating rows: Start by making a row of overlapping zucchini slices, standing them vertically on edge. Follow with a row of eggplant, then a row of tomatoes in the same manner, packing the rows tightly together. Continue until the baking dish is filled. Sprinkle the surface of the vegetables generously with salt and pepper, and drizzle with olive oil.
- Bake uncovered for 15 minutes. Reduce heat to 350° and continue baking for 45 minutes to an hour, or until the vegetables are quite tender. Cool dish to room temperature to allow flavors to meld—the tian absolutely tastes best at room temperature. To serve, garnish with torn basil leaves.