Tomato, Squash, and Eggplant Tian

Article written and reviewed by Tara Kemp, PhD
Published October 9, 2025

Eggplant: A Hidden Secret of the Veggie World

Eggplant is a less-commonly used vegetable. Because of that, people are often uncertain how to cook it. Once you learn to use it strategically, it’s actually an amazing way to distribute flavors and add richness in a meal. This recipe gives you the opportunity to make sure you prepare it in a way that tastes delicious!

Eggplant is rich in antioxidants and polyphenols, especially nasunin (found in the deep purple skin) and chlorogenic acid. Eggplant helps fight oxidative stress in the body and reduces inflammation linked to chronic disease. In addition, eggplant delivers a range of essential vitamins and minerals, including vitamin C for immune defense, vitamin K for bone health, vitamin B6 for energy metabolism, potassium for healthy blood pressure, and manganese for antioxidant function. And, like most vegetables, it brings all these nutrients along with fiber in a low-calorie package.

Tomatoes Tie It All Together

Tomatoes bring this dish to life, with juicy acidity and natural sweetness that bring together and enhance the other flavors, particularly from the zucchini and onions. When roasted, the tomatoes become saucy, making it a moisture-rich dish that melts in your mouth.

Tomatoes are known for being a great source of the carotenoid lycopene, which gives them their red color. Lycopene is one of the most potent antioxidants – it’s twice as effective as beta-carotene and ten times more potent than vitamin E at neutralizing harmful molecules that contribute to cell damage and inflammation. Lycopene and other compounds in tomatoes have been shown to have anti-diabetic effects as well as prevent complications from diabetes.

Zucchini

In this recipe, zucchini balances out the eggplant, onion, and tomato with its soft, tender bite and mild flavor.

Research shows that zucchini seems to have a dual benefit for health, in which it protects healthy cells from oxidative damage, while also having a destructive role against unhealthy (cancer) cells. Pretty amazing!!

The best case scenario for this dish is to use eggplant, tomatoes, zucchini, and onion with a similar width so that the vegetable slices can be layered in a uniform way.

Each of these vegetables is so flavorful that all you need to bring it all together is the fresh herbs, garlic, and lemon juice. Once you catch a whiff of the aroma as it bakes you’ll know what we mean! 

Tomato, Squash, and Eggplant Tian

Get ready for a guilt-free, gourmet eating experience!
Prep Time 30 minutes
Cook Time 1 hour 30 minutes
Total Time 2 hours
Servings 2
Calories 230 kcal

Ingredients
 

  • 8 (984g) Tomatoes (medium-sized, sliced thin)
  • 1 (150g) Red Onion (large-sized, sliced thin)
  • 3 (323g) Zucchini (large-sized, sliced thin)
  • 1 (572g) Eggplant (medium-sized)
  • 2 tsps (1g) Fresh Rosemary - Available in small bunches
  • 2 tsps (2g) Fresh Thyme - Available in small bunches
  • 3 (9g) Garlic Cloves (minced) - About 1 bulb
  • 3 tbsps (48g) Lemon Juice - Juice from 1 lemon

Instructions
 

  • Preheat the oven to 375 degrees.
  • Combine the vegetables in a large bowl and season with pepper, to taste. Sprinkle vegetables with 1-2 Tbsp water, then sprinkle with chopped rosemary and thyme leaves. Toss gently with lemon juice and garlic.
  • In a 13x9 baking dish, arrange the vegetable slices in rows in the following order: tomato, eggplant, tomato, squash, onion, tomato, eggplant, tomato, etc. Each eggplant slice should be touching a tomato slice on either side. Do not lie the vegetables flat; try to stack them when arranging them in the dish (with the rounds slanting to one side after arranged in dish).
  • Add extra herb sprigs to the dish. Pour any juice left in the bowl on top the vegetables in the dish and tightly cover with tinfoil.
  • Put the preheated oven to bake for 1 hour. After 1 hour, remove the foil and continue to bake for another 30 minutes until the vegetables are completely tender and slightly colored on the edges.

Nutrition

Calories: 230kcalCarbohydrates: 51gProtein: 10gFat: 2.2gFiber: 18g

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About the author 

Tara Kemp, PhD

Tara Kemp, PhD is a contributing writer for Mastering Diabetes. She is a mental health coach, researcher, and writer. Tara received her PhD in Psychosocial Health from Northern Arizona University and has a background in nutrition education with previous positions at organizations like Forks Over Knives, the Physicians Committee for Responsible Medicine, and Plant-Strong. Tara is also the founder of Reconnect Collective.

Tara’s research specialization is the foundations and mechanisms of a healthy relationship with food, body, and self. She was the principal investigator and lead author of the groundbreaking INFINITE study, which explored the role of food and nutrition in recovery from substance use disorders. During her doctorate program at Northern Arizona University, she was involved in the Nutritarian Women’s Health Study, and her dissertation research focused on how a plant-based diet influences individuals’ recovery from disordered eating.

Tara’s work combines evidence-based practices from various disciplines to support people in addressing the root cause of their challenges while also building the foundations and skills of mental health to cultivate lasting well-being.