This is the perfect side dish to serve when you are trying to decide what to do with yet another harvest of zucchini and summer tomatoes.

zucchini, tomato and rice gratin
It is also a vegetarian main dish (that’s how we had it) with a big green salad. But you could also serve it as a side dish at a summer BBQ or as a seasonal breakfast dish with a poached or fried egg on top.
If you have the zucchini and tomatoes available, the rest of ingredients are standard pantry staples. I used brown rice but white rice would work perfectly as well. If you have some leftover rice from dinner earlier the week, this comes together quite easily.
I want to make a note about salt. Not all salts are the same. I use almost exclusively Diamond kosher salt in cooking. It doesn’t have any additives or anti caking agents. The grains are slightly larger so I would use more of it in a recipe calling for fine sea salt or regular table salt or even another brand of kosher salt. The amounts in the recipe are designed for Diamond kosher salt (yes, as one commenter reminded me, there is a difference in the grain sizes of kosher salts. Morton brand kosher salt grains are smaller). If you are using another type, please use less and taste, taste, taste. You can always add more later but an over-salted dish is difficult to reclaim.
Zucchini, tomato and rice gratin
serves 4-6 as a side dish
Ingredients:
- 1/3 cup of uncooked rice, cooked and cooled
- 5 Tablespoons of olive oil
- 1 1/2 lbs zucchini, 3-4 medium, sliced 1/4 inch thick
- 4-5 medium tomatoes, sliced 1/4 inch thick
- Salt and pepper
- 1 medium onion, halved lengthwise and thinly sliced
- 3 medium garlic cloves, minced
- 2 large eggs, lightly beaten
- 1/2 teaspoon dried thyme
- 1/2 teaspoon dried oregano
- pinch of red pepper flakes
- 1/2 cup of grated parmesan, divided in half
Method:
- Heat your oven to 450 degrees F. Cook your rice by you favorite method.
- Line 2 sheet pans with parchment paper and lightly coat them with olive oil. Spread the zucchini slices on one sheet and the tomato slices on the other, trying to not overlap the slices. Sprinkle each with salt and a few grinds of pepper.
- Roast the tomatoes and zucchini for 10 minutes and remove the tomatoes from the oven. Flip the zucchini slices and return the pan to the oven for another 10 minutes. Leave the oven on.
- Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the onions, garlic and 1/4 teaspoon of salt to the pan. Cover and reduce the heat to low. Cook until the onions are limp and tender, 15-20 minutes.
- Grease a shallow medium casserole dish (about 2 quart size) with a tablespoon of olive oil.
- In a bowl combine the onion mixture, rice, eggs, spices, 1/2 tablespoon of olive oil, and half the parmesan.
- Spread half the rice mixture in the bottom of the casserole, cover with half the zucchini, spread the remaining rice on top, then the rest of the zucchini, finish with the tomato slices. Sprinkle with the remaining parmesan. I was a little generous with the parmesan on top.
- Bake until golden brown, about 20 minutes. I found the best browning is on the shelf near the top of my oven.

zucchini, tomato and rice
This recipe was inspired from one in the the blog Smitten Kitchen, I have made my own modifications. It was originally published by SK in 2012; she adapted it from a recipe published in Gourmet in 2008. But it really feels like came from a small provincial kitchen in Italy or France. Don’t make it too fancy, it should be rustic.
Sounds and LOOKS fantastic Liz!! Cant wait to try it!
Thanks Dianne, hope you are safe and well ❤️
A perfect summer dish! There is also a difference between kosher salts – Diamond versus Morton with a much finer grind.
You are correct, I use Diamond as that is what’s available here.
This recipe reads delicious!! Almost like a hearty casserole..Yumm
We ate it as a main dish, it is hearty. And I liked the leftovers heated in the microwave with an egg on top.
Wonderful. I was sure hoping this would be a better garden year than last, but nope. Too much rain. But I can always purchase tomatoes and zucchini!
Lucky you with the rain, I pray for an early wet season here. My husband is harvesting zucchini for me as I have been gone for a week and I think he has filled 2 refrigerators. And to add more, he told me out CSA included more zucchini. I definitely need ideas on how to use them, and not recipes that only include 1 or 2!
I always make zucchini pancakes, but I only use 2 or 3.
Good idea, I will look for a recipe. It sounds good. I have seen zucchini fritters as well and may try those.
Perfect timing Liz. A friend with an over active garden gifted us a bag of zucchini and patty pan squash. I love rice casserole dished so your zucchini, tomato and rice gratin is on the menu for coming weekend…
Let me know how you like it Ron.
No garden so I have to buy my zucchini but I made a zucchini gratin recently with zucchini only. This version sounds really good, thank you!