Zucchini and Spinach Gratin

The recipe calls for bacon and I think it's an important flavor component. For those of you who don't eat pork, or meat, you can substitute butter and or olive oil (a couple tablespoons) to sauté the onions.

  • Prep time: 40 minutes
  • Cook time: 1 hour
  • Yield: Serves 4 to 6


  • 2 pounds zucchini
  • Kosher salt
  • 1 pound frozen spinach*
  • 3 slices of thick cut bacon (about 3 ounces), cut crosswise 1/4-inch pieces
  • 1 large onion
  • 1 handful of parsley (about 1/2 cup of leaves, lightly packed)
  • 3 cloves garlic, peeled, coarsely chopped
  • 1/2 cup freshly grated Parmesan cheese
  • Freshly ground black pepper
  • 3 eggs
  • Extra virgin olive oil

* Or 6 packed cups of fresh chopped spinach leaves, blanched and drained


1 Grate and drain zucchini: Grate the zucchini. Toss the grated zucchini with about a teaspoon of Kosher salt. Place the grated zucchini in a large sieve (or colander) placed over a bowl to catch the water as the salt helps the zucchini release its moisture.

Let sit for 30 minutes or so, then squeeze out the remaining excess moisture with paper towels or a clean tea towel.

2 Thaw and squeeze the spinach: Thaw the spinach, let drain while the zucchini is draining. Then squeeze out the excess moisture with paper towels or a tea towel.

3 Cook the bacon: Heat a large skillet on medium heat. Add the bacon and gently cook until lightly browned and most of the fat rendered out, about 10 minutes.

4 Add onions: While the bacon is cooking, peel and finely chop the onion. Add the onions to the bacon and cook for an additional 10 minutes, until the onions have softened.

5 Prepare parsley and garlic (persillade): While the bacon and onions are cooking, prepare the parsley and garlic. Place the parsley and garlic with a small pinch of salt into a food processor and pulse just a couple of times.

pulse parsley and garlic in a food processor

6 Preheat the oven to 350°F.

7 Prepare the filling: Place the zucchini into a large bowl. With a wooden spoon, mix in the cooked onions and bacon. Mix in the spinach, parsley, and garlic. Mix in half of the Parmesan. Taste, and add black pepper and more salt to taste. Mix in the eggs.

filling for spinach zucchini gratin

8 Fill gratin pan: Coat the bottom and sides of a 2 quart casserole or gratin dish with a tablespoon of olive oil. Put the zucchini spinach mixture into the dish and pack it down. Sprinkle the remaining Parmesan cheese over the top and drizzle with a little olive oil.

zucchini spinach gratin about to be cooked

9 Bake: Bake in a 350°F oven for 40-45 minutes, until the top is nicely browned. Serve immediately. Reheats well.

zucchini spinach gratin right out of the oven

Click on the comments you'd like to print with your recipe. Grayed out comments will not print.



    Since first trying this recipe, I make it all the time. Veggie licious, low carb, everything I want in a dish. Thank you so much!


  • Kathy J

    Wonderful recipe! Sunday breakfast this morning, the whole family enjoyed it. The only things I would change are cooking the garlic and adding some cheddar on top. Very yummy, would work as an appetizer also.


  • Sonali

    I tried it today without the bacon, but caramelised the onions a bit with sugar. It was fantastic!

  • Kevin

    I made this yesterday using one zucchini, one yellow summer squash and a bag of fresh spinach.
    Outstanding recipe. (as usual)


  • Tami

    Oh so delicious! What a great way to use the zucchini crop. Loved the bacon and parm.


  • Marcy

    Wow, oh wow, oh wow, oh wow! I made this for my boyfriend’s birthday dinner and served it along with roasted plum tomatoes and bacon wrapped sirloin fillets. I was promptly told I could throw out every potato au gratin recipe I’d ever made and serve this in it’s place. It’s even reserved for a spot on the Thanksgiving dinner table!


  • Shirin

    This is an amazing recipe!! I have made it twice in the course of a week, always with rave reviews!! The last time it was for a party of almost 30 diners and they polished it off and went for seconds. So healthy, yet delicious!!
    Thanks Elise for such a fabulous recipe. :)


  • Judy Goodwin

    I made the Gratin for dinner tonight and loved it. I substituted beet greens for the spinach since I had them in my garden. Also used half zucchini and half summer squash…very colorful and delicious!


  • Papaya

    Just made this tonight, and it was really good! We have an abundance of kale in our garden so we used that instead of spinach. Great way to eat veggies.


  • Jim

    I’ve made this at least four times since you’ve posted it. Made it a little more decadant, though. Added pancetta to the bacon, cream to the eggs, more parm, and added gruyere. Probably doesn’t count as a veggie dish anymore, but it’s awesome!! I make it in big ramekins, turns out great.

  • Laine

    Elise – I’m also tempted to turn this into individual souffles. I think using a smaller amount of the veggie mixture, and folding in a couple stiffly beaten egg whites might do it for 4 or 6 ramekins. Have you tried something like this?

    I have not tried this as individual portions or as a souffle. But if you do, please let us know how it turns out for you! ~Elise

  • Laine

    Sorry to be joining in so late on this one – it looks great and I’ll be trying it tomorrow. Thanks, Elise!

    I’ve also thought of a variation on this for a brunch dish, that I want to try: skip blending in beaten eggs; place the mixture in the gratin dish; make three or four little depressions in the mixture and gently drop a whole raw egg in each depression; bake. The veggies will be more like a sauce, but it seems like it should be really good.

  • eve

    I followed this recipe to the letter.Was deligent about draining liquid from shredded zucchini. The gratin looked just like photo but once it was cut into it was liquidy. We did not like the consistency & it was too garlicky off setting all other flavors. I will try again using 2 eggs,less garlic,& a mix of gruyere & parm regg.
    Bon Appetit!

  • Amy

    This was good but I think the parsley was a bit much for me. Next time I’ll try it with thyme or rosemary and see if it suits my palate a bit more. Great way to use up the veggies- thanks for sharing!

  • Mom of Five

    I made this tonight as a side dish and it was a hit with all of my kids; the only change I made was the amount of cheese. Sadly, we are a little excessive with our love of fromage and I tripled the amount to one and a half cups. It was perfect! I served it with grilled chicken and a bowl of cherries for dessert. Thanks so much for a great recipe!!

  • Joe Benson

    I did this for my big family BBQ yesterday and it was a big hit. I was not able to use the bacon since we had non meat eaters and also used kale and chard (I just cooked it a bit before adding), put it together the day before and cooked it a hour before dinner. In hindsight, I would have cooked it a day ahead an reheated it. Very good recipe, thanks so much for posting it.

  • JB

    This is delicious! I added shredded cheese and mix it up and added Parmesan on the top. Also I use Callaloo, which is from the Spinach Family.

  • Joce

    Made this for dinner tonight and used a mixture of parm and asiago cause that is what I had on hand. YUMMY!


  • Nicole

    Do you think this would freeze well? Before or after baking?

    Don’t know, but if you try it, please let us know how it works out for you. ~Elise

  • Barbara

    Had this w/grilled CSA vegs tonight and was a little concerned about the negative comments, but we loved the recipe; may have been a little heavy on the garlic and parm and a little light on the zucch (1 1/2 lbs) but it was terrific for our (almost) vegetarian Thursdays. Thanks for the idea!

  • Jim

    Excellent recipe. We didn’t come close to finishing it with dinner, so I used the some of leftovers in an omelette with some sauteed mushrooms and swiss cheese for breakfast the next morning. Really tasty!

  • Lane

    I made this with less zucchini (because I’d used it all earlier in the week!) and subbed in some grated carrots. I also added sliced potatoes to make it a main dish.

  • HML

    I used yellow summer squash instead, and basil instead of the parsley (what my CSA and farmer’s market were full of this week) and added a handful of cracker crumbs in with the topping. It was great, and the leftovers were maybe even better!

  • Leslie

    Was excited for the dish to pop up when it did, my daughter has been troubled eating meat lately and this would be easy on her stomach and full of good stuff. Unfortunately, it turned out to have very little flavor beyond the zuchinni iteself. I may try again with basil, mozerella and chopped tomatoe.

  • Mellen

    Great recipe. I had vast quantities of veggies left over from last week’s CSA share. I used zucchini and summer squash. Shredded broccolini to substitute for the spinach. Cut the kernels from five ears of corn off the cob and mixed those in. Used basil instead of parsley. And mixed in some gruyere with the parmesan. It was a big hit. Even the three year old wanted more!

  • Maja

    I made this today, and the Potatoes Provencal, all with fresh vegetables and herbs I bought at the Farmer’s Market under the freeway. Just finished a plate and it is DEEElicious. I played on it a bit, used half yellow zucchini and half green, and then mixed the parmesan topping with some hand crushed panko and a bit of olive oil. Great dish. I will definitely make it again. Thanks.

  • Tim

    I normally love Simply Recipes’ recipes, but this one didn’t do it for me. Needs to be creamier, I thought. I followed the directions reasonably well, and I love spinach ans zucchini, so I think it’s just a preference thing. I’m probably a heathen.

  • Lauren

    Would it be possible to use a different sort of green, like collard greens or turnip greens? I got a lot of them in my CSA box this week, and I have no clue how to use them.

    Sure! Swiss chard would be great in this, or kale. By the way, if you are looking for other ideas for your greens, check out our greens recipes. ~Elise

  • Amanda

    Thank you, thank you, thank you! I made tis tonight to go with a pork loin and some roasted orange/maple butternut squash, oh it was so very good! I wasn’t sure how well it would mesh with the butternut, but the salty goodness actually went quite well with the sweetness of the squash. Once again, you have outdone yourself and provided me with a yummy dinner!


  • Barbara Ann

    If you were to use this as a side dish what would be a good accompaniment? Thanks.

    I think roasted chicken would go well with this. ~Elise

  • ML Chan

    Anybody can think of a good parmesan substitute, can’t do dairy? Thanks!

    Use seasoned bread crumbs, and drizzle with olive oil for the topping. And just skip it in the filling. ~Elise

  • radz

    Can’t wait to try out. Sounds delicious!
    Can I substitute Parmesan with some other cheese? Any suggestions? Thanks

    Try it with Gruyere. ~Elise