Zucchini, Eggplant, Tomato Gratin

Oh my. Look who’s getting all fancy with the vegetables! It’s as if my garden decided to throw a prom, and the eggplants, zucchini, and tomatoes banded together to show everyone else up. (Clearly they deserve best prize for something, don’t you think?)

Normally I would look at something like this and think it’s waaaay too complicated. But this summer vegetable gratin is actually quite straightforward. To prepare these vegetables, you have to cut them anyway, so why not cut them in rounds and arrange them in a pretty pattern?

Zucchini Eggplant Tomato Gratin

If you recall, Remy, the “little chef” in Pixar’s Ratatouille movie, prepared something similar for Anton Ego, the food critic. This isn’t that dish, but something much easier. You just sauté onions and bell peppers, layer them at the bottom of a casserole dish, top with rounds of eggplant, zucchini, and tomato. Top that with cheese and bake!

It’s a lovely, easy, colorful presentation for our favorite summer vegetables. A perfect side to take to a party.

Zucchini, Eggplant, Tomato Gratin Recipe

  • Prep time: 20 minutes
  • Cook time: 1 hour, 10 minutes
  • Yield: Serves 6 to 8.

We're topping this gratin with provolone and Parmesan cheeses. You could easily top it with Gruyere instead. For a more Provencal approach, skip the cheese all together and top with bread crumbs, minced garlic, parsley, and olive oil.



  • 3 Tbsp olive oil
  • 2 cups sliced yellow onion (1 large onion)
  • 1 cup of sliced red, orange, or yellow bell peppers
  • 1 long eggplant (a slender eggplant like a Japanese eggplant, not a large globe, about 1/2 pound)
  • 1 large zucchini (about 10 to 12 inches long, 1 1/2 inch diameter, about 1/2 pound), or other summer squash
  • 2 medium sized tomatoes
  • 3 cloves of garlic, peeled and smashed
  • 1 1/2 teaspoons salt
  • 2 Tbsp chopped fresh parsley
  • 2 ounces Provolone cheese, sliced or grated
  • 3 Tbsp grated Parmesan cheese


saute peppers and onions spread peppers and onions out in an even layer

1 In a large sauté pan heat 2 Tbsp of the olive oil on medium high heat. Add the sliced onions and cook until lightly browned, stirring frequently, about 10 minutes. Add the sliced bell peppers and continue to cook with the onions until the bell peppers are softened and the onions are well browned, about 5 to 6 minutes more. When done, transfer the onions and bell peppers into a large gratin pan or casserole dish.

2 While the onions and peppers are cooking, slice the eggplant and zucchini in 1/4-inch thick round slices. You'll also want to slice the tomato into 1/4-inch thick slices, but depending on how big your tomato is, you may need to cut the tomato in half or in quarters first. All of the sliced vegetable pieces should be about the same size to make it easier to layer them in an attractive manner.

top with slices of eggplant, zucchini, tomato continue to top with slices of tomato, eggplant, zucchini in an attractive pattern

3 Preheat the oven to 350°F (175°C). Spread the cooked onions and bell peppers in an even layer at the bottom of the gratin dish. Place the mashed garlic on top of the onions and peppers. Arrange the slices of the eggplant, zucchini, and tomato on top of the cooked onions and peppers, alternating the vegetables, in an attractive pattern, stacking them and fanning them across the surface of the dish.

top with cheese

4 Sprinkle with salt and parsley. Top with Provolone and Parmesan cheeses. Drizzle the remaining tablespoon of olive oil around the perimeter, where the vegetables meet the side of the dish.

5 Cover with foil (it helps to grease the underside of the foil with a little olive oil so that the cheese as it melts does not stick to the foil). Bake for 40 minutes at 350°F (175°C). Remove the foil. Turn on the broiler and broil for 5 minutes or until nicely browned.

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Zucchini Eggplant Tomato Gratin


  1. ~Nancy

    I showed this dish to my girls and they freaked out! We have watched Ratatouille countless times and each time we see Remy’s gorgeously beautiful dish made for Ego, we drool in amazement. How can they make an animated dish look so lusciously good? And here you have captured it in real life. I’ll be making this dish, much to the delight of my girls ages 4 & 7. Thanks for your wonderful food blog and all the wonderful dishes I’ve made courtesy of you and your guest bloggers!

    • Jane H

      Nancy, that is so cool and so sweet, and it is the first thing I thought of when saw the picture of the dish! (But I am 52 and neither 4 nor 7, and I sooo love that movie!)

  2. Derek the Zen Chef

    You do make it seem so easy; good job of making use of that garden produce! Here in Japan, my zucchini are very fecund, but suffer mightily from mold, since it sib bold hot AND super humid here. I end up with lots of them getting as long as a ballpoint pen no sooner than getting fuzzy and rotten… Ah I recall, you are in drought-stricken California and probably have no such blight, right!
    Parmesan and provolone are my favorites, and I also like how you went easy on the cheese – just a bit goes a long way. Best,

    • Jody K

      Derek, it might also be that they aren’t being pollinated. I lost mine until I started pollinating the female flowers with pollen from the males. I use a paintbrush, it’s the first thing I do each morning. We have a terrifying lack of bees in SE Pennsylvania.

      • Sandy S

        Hi Derek, in addition to what Jody has said, here are few things that might help. One is to only water the ground below the plants. And the 2nd is to keep handy a spray bottle with a solution of baking soda in water (teas./quart or 1 tbsp./gal.) to spray the plants several times a week and always after a rain. In my experience, it is also important to never let the plants go thirsty. That seems to weaken their resistance. And finally, if possible set up a fan to keep a slight breeze on the plants during humid periods.

  3. PinchOfLime

    This is so beautiful! And it sounds so good. I have quite a few zucchini and romas from my garden so I think this is on the list for dinner this week!


    delicious! I prepare something similar with tuna.

    • Emma

      Tuna is a great idea, i’ve been trying to keep my protein intake high so using some tuna in this would really suit me.

  5. HappyForks.com

    It looks like late summer on the plate. Classic but still amazing combination of vegetables. If we forget about cheese and we add against them something crispy like nuts or seeds, we have a healthy lunch and no worries about saturated fat and cholesterol

  6. Sandy S

    Love the look and ingredients of this recipe Elise! If I can tear myself away from microwaving corn on the cob! I will try it later this week. Looks like it would go good with either fish or chicken… maybe your Grilled Lime Chicken?

  7. Laura

    I love this dish for 2 reasons!!

    1.) I grew all these veggies myself in my garden, eggplant included and they’re all organic veggies!! yay.

    2.) It’s a great excuse to use the mandolin my mom gave me for Christmas (I think it was supposed to be taken as a hint to cook more.)

    Cool, thanks =)

  8. Walter Underwood

    Oh dear, this was good. I rubbed the leaves off a few sprigs of thyme on top of the onions. And I cooked it uncovered to reduce the flavors a bit. With some bread crumbs on top so it wouldn’t burn. Everyone enjoyed it.

  9. Hayley

    I am making this dish tonight for dinner, I do not have a gratin dish, but I have a 2qt casserole dish and a 3 qt casserole dish. I hope those will work in place of the gratin dish! Any advice is welcomed!

  10. Jan

    Thanks for the recipe. I’ve made it today and it was tasty!
    Coincidentally, on lunch break at work, I was in the restaurant near by and they also served eggplant with cheese (but it was sliced horizontally and baked).

  11. Nina D

    Hi, Elise,

    This sounds really good and I actually have everything on hand to make it, but can’t work it into the menu plan until tomorrow night, and we will be out most of the day. Can I get it set up ahead (saute the peppers and onions, lay out the veggies top with the cheese) store it in the fridge and then bake it off tomorrow? I’m wondering if the eggplant, especially, might brown once cut.

    What do you think?

    • Elise

      Hi Nina,
      Yes the eggplant may brown a little. But I don’t think it will make much of a difference to the taste, and it will be doused in cheese, so it will be hard to see anyway.

      • Nina D

        See? There’s always a good reason to douse anything in cheese! Thanks, Elise.

  12. shreddie

    I made this tonight on the grill with the lime/cilantro chicken. What a hit! I modified the recipe a bit. I omitted the peppers and I left the onion raw for the bottom layer. I used Roma tomatoes, and I brushed the assembled veggies with olive oil and the crushed garlic. I put everything in a pie tin covered with foil and put it on the grill for about 40 minutes. I added the cheese before serving. There wasn’t any browning under the broiler, but it was still very pretty.

  13. Amanda

    This recipe was able to satisfy 3 meat lovers!!!! I skipped on the parsley and provolone cheese and only added a small amount of parmesan and it still turned out great.

  14. Amanda

    I’m going to be making this for a family reunion potluck this weekend full of relatively generic meat and potatoes eaters…we’ll see what happens!
    I’ve loved every recipe I’ve made of yours, Elise, so either way, if it doesn’t get eaten much, then I’ll have leftovers to enjoy!

  15. Lillian

    Leave it to my German oven to complicate this simple recipe. One hour in and the veggies are still crunchy. It looks pretty however.

  16. Victoria

    I have never cooked eggplant before. When you cut it open do you need to take any seeds or pulp out? Does it need to be peeled?

    • Elise

      No, you do not need to take out any seeds or pulp. The “pulp” is what you are going to eat. Some thick-skinned eggplants you may want to peel. It depends on the eggplant. For this recipe we are using narrow eggplants with relatively thin skins, so we did not peel them.

  17. victoria


    thank you I am looking forward to trying this dish very soon.

  18. Sandy

    My brother and I made this yesterday for the family ^_^. Followed by sister and I making your Eggplant Parmesean for today’s lunch and both were delicious. I unfortunately could only find the big eggplant so they didn’t cook as fully as the zuchinni or make the dish pretty like yours but everyone still cleaned their plate.

  19. Joan small

    I made the dish
    Followed instruction
    I bought small eggplant
    But still the eggplant was tough
    broil it 5 minutes
    It looked perfect
    WHat did I do wrong

    • Elise

      You need to bake the dish for 40 minutes and then broil it for 5. If the eggplant is still tough after that, it could be a particularly tough individual eggplant that just needs more cooking.

  20. Sujata

    Hi Elise. I am happy I stumbled onto your beautiful blog. I love this recipe. I am from India, and was thinking of using some spices with the veggies. At what stage can I use the spices – Spices – crushed dry red chili, minced garlic, minced ginger, cilantro, aniseed, and lemon juice after the dish is cooked. Thanks for your advice.

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