Mediterranean Roasted Vegetable Tian

Key Equipment Needed

• 10-inch or 11-inch oval baking dish (or round cast-iron skillet)

• Mandoline slicer (set to 1/8-inch thickness) or a sharp chef’s knife

• Large skillet (for cooking the onion base)

• Parchment paper (cut to fit inside the baking dish)

Ingredients

For the Caramelized Onion & Garlic Base

• 2 tablespoons extra virgin olive oil

• 1 large yellow onion, thinly sliced

• 4 cloves garlic, finely minced

• 1 can (14.5 oz) crushed Italian crushed tomatoes (or fire-roasted tomatoes)

• 1 teaspoon dried oregano

• ½ teaspoon red pepper flakes (optional, for mild heat)

• Kosher salt & freshly cracked black pepper, to taste

For the Vegetable Layers

• 2 medium zucchini, sliced into 1/8-inch rounds

• 2 medium yellow summer squash, sliced into 1/8-inch rounds

• 2 medium Japanese eggplants (or long slender Chinese eggplants), sliced into 1/8-inch rounds

• 5-6 medium Roma tomatoes, sliced into 1/8-inch rounds

• 3 tablespoons extra virgin olive oil (for drizzling)

• 1 tablespoon fresh thyme leaves (or 1 teaspoon dried thyme)

• 2 tablespoons fresh basil, chiffonade (for garnish)

• Kosher salt & black pepper, to taste

Step-by-Step Cooking Instructions

Step 1: Prepare the Oven & Dish

Preheat your oven to 375°F (190°C). Lightly coat the interior of an 10-inch or 11-inch oval ceramic or glass baking dish with 1 teaspoon of extra virgin olive oil. Set aside.

Step 2: Build the Tomato & Caramelized Onion Base

Heat 2 tablespoons of extra virgin olive oil in a large skillet over medium heat.

Add the thinly sliced yellow onions and a pinch of salt. Sauté for 8 to 10 minutes, stirring frequently, until the onions soften and turn a golden caramel brown. Reduce heat to low if the onions begin to crisp or burn around the edges.

Add the minced garlic, dried oregano, and red pepper flakes. Cook for 1 minute until fragrant. Pour in the crushed tomatoes, stirring to combine with the onions. Season with ½ teaspoon of kosher salt and ¼ teaspoon of black pepper.

Simmer over medium-low heat for 5 minutes until the sauce thickens slightly. Remove from heat and spread the mixture evenly across the bottom of your prepared baking dish.

Step 3: Slice and Prep the Vegetables

Using a mandoline slicer or a very sharp chef’s knife, slice the zucchini, yellow squash, eggplant, and Roma tomatoes into uniform 1/8-inch rounds.

Pro Tip: Select vegetables with roughly the same diameter so the slices align neatly in the dish.

Place the eggplant slices on a paper towel, sprinkle lightly with salt, and let sit for 10 minutes to draw out excess moisture. Pat dry before assembling.

Step 4: Assemble the Tian

Working in a repeating sequence, stack one slice of eggplant, one slice of yellow squash, one slice of zucchini, and one slice of Roma tomato.

Arrange the slices vertically (standing on edge) along the outer border of the baking dish, overlapping them tightly like shingled roof tiles. Continue layering in concentric circles toward the center until the entire dish is packed tightly with vegetables.

Step 5: Season and Bake

Drizzle the remaining 3 tablespoons of extra virgin olive oil evenly over the arranged vegetables. Season generously with kosher salt, freshly cracked black pepper, and fresh thyme leaves.

Cut a piece of parchment paper to fit directly over the vegetables inside the rim of the dish. Cover tightly with aluminum foil over the entire dish.

Bake covered at 375°F (190°C) for 40 minutes. The parchment and foil trap steam, softening the thick-cut vegetables evenly.

Remove the foil and parchment paper. Return the dish to the oven uncovered and bake for an additional 20 to 25 minutes, until the vegetables are tender, the edges are lightly golden and charred, and the tomato sauce below is bubbling around the sides.

Step 6: Rest and Serve

Remove the tian from the oven and let it sit at room temperature for 10 minutes before serving. This allows the juices to settle so the slices hold their shape when plated. Garnish with fresh basil ribbon strips just before serving.

Chef’s Tips for Success

1. Uniform Slicing Matters: Using a mandoline ensures every vegetable slice cooks at the exact same rate. Thicker slices won’t soften enough, while inconsistent cuts make tight layering difficult.

2. Moisture Control: Eggplants and squash hold high water content. Baking covered first steams them through, while the uncovered phase burns off excess liquid so your base sauce stays thick rather than watery.

3. Make Ahead Friendly: You can assemble the entire tian up to 24 hours in advance. Cover tightly with plastic wrap and store in the refrigerator. When ready to bake, remove the wrap, cover with parchment and foil, and add 5–10 minutes to the covered baking time.

Nutrition Information

Calculated per serving (1/6th of total recipe).