Zucchini and Spinach Gratin

Another week, another refrigerator drawer filled to the brim with garden zucchini. Sound familiar? To take a break from our usual (almost daily in the summer) way to cook up the zucchini (see mom’s summer squash), we prepared a classic French gratin, with grated zucchini, spinach, onions sautéed with bacon, a persillade of parsley and garlic, all bound together with a few eggs, tossed with Parmesan, and baked until golden brown.

Zucchini has never tasted so good.

I think the bacon might have something to do with it. And maybe the Parmesan. And the onions, and garlic. Okay, everything. The combination is perfect.

The recipe looks more involved than it is. Most of the time is in the baking or in the allowing the zucchini and spinach to drain excess moisture. The hardest part is grating the zucchini (a breeze if you have a food processor) and the Parmesan. The trick to a successful recipe is squeezing out as much moisture as you can from the zucchini and spinach. Tossing the zucchini with salt and allowing it to drain for half an hour will help draw out a lot of its moisture. If you don’t do this I’m guessing that you might end up with something that is too loose, with too much moisture for the eggs to do their work as a binder.

Best part? The recipe uses two whole pounds of zucchini! Which in our case should use up at least a day or a day and a half’s worth of garden produce. Enjoy. ;-)

Zucchini and Spinach Gratin Recipe

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

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.



  • 2 lbs zucchini
  • Kosher salt
  • 1 lb 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
  • Olive oil

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


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

3 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 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 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.

6 Preheat the oven to 350°F.


7 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.

8 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.


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

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Inspired by a gratin recipe in Provence: the Beautiful Cookbook.


Zucchini and chard gratin - from Local Kitchen Blog

Showing 4 of 31 Comments

  • 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

  • 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

  • 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

  • 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!

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