Super Easy Summer Squash Gratin

super easy summer squash gratin

This time of year I suspect few of you are thinking about summer squash. Many of you are more likely celebrating the last prune plums of the season or refusing to eat anything but tomatoes before they disappear for too many long cold months. And some of you may have already moved on to pumpkins and apples.

But it’s been an odd summer for me. I just haven’t had my summer squash fill. So last Sunday at the Schenectady farmers’ market, I stocked up — they’re practically free at the market these days — with visions of spending the week making bread and fritters and spaghetti and salads with shaved Pecorino.

But I’m not sure I’ll be getting to any of these dishes anytime soon, because tonight I will be making this gratin for the third evening in a row, and I have enough squash on hand to carry this trend through the weekend. This gratin couldn’t be simpler to throw together, and unlike so many gratins, this one is not laden with cream and cheese. A third cup of grated Parmigiano (or whatever cheese you have on hand) along with a cup of fresh bread crumbs form the crispy — irresistible — topping, and a layer of sautéed onions or tomatoes (as the original recipe suggests) and thinly sliced summer squash form the foundation.

Of course the seasonings can be dolled up with garlic or herbs or minced anchovies, and after you’ve made this once, you’ll start wondering how you might adapt this gratin later this fall, perhaps with sautéed kale or green beans or leftover cannellinis.

The important thing to keep in mind here is that you can’t mess this up. The layer of vegetables can be thin or thick. There’s no perfect ratio of squash to topping. This dish is rustic. It’s fast. It’s easy. Go wild. Doesn’t summer squash deserve one last hurrah? By the weekend we’ll be dreaming about Paula Reds, Ginger Golds and Jonamacs.

prosciutto, arugula and pecorino pizzaOne last note: As many of you know, I am loving my Baking Steel. Since it has arrived, I have made some sort of pizza or flatbread at least once a week, and from here on out, I will be sharing my pizza creations over on the Baking Steel blog. Here is the first: Individual Flatbreads with Prosciutto, Arugula and Pecorino.

summer squash

This is a good time to break out your favorite mandoline:
sliced squash

topping ingredients

breadcrumbs and cheese topping


sautéed onions

topped with summer squash

ready for the oven

just baked

Summer Squash & Onion Gratin

Serves 2 comfortably if it’s the only side dish; Serves 3 to 4 if there are some other options
Adapted from this Bon Appetit recipe

1 large onion, thinly sliced
4 Tbsp. olive oil, divided
1 cup fresh breadcrumbs
1/3 cup grated Pecorino or Parmigiano Reggiano or whatever you have on hand
kosher salt and freshly ground black pepper
2 summer squash (large or small), thinly sliced (to yield 8oz (225g) to 12oz (340g) or 2 to 3 cups)

1. Heat 2 Tbsp. oil in a medium ovenproof skillet over medium heat. Add onion; cook, stirring occasionally, until onions are soft and starting to caramelize, 10 to 15 minutes. Note: if you have time to really allow the onions to caramelize at a slow pace, do so; if you don’t, just sauté the onions until they are soft. Season with salt and pepper.

2. Meanwhile, toss breadcrumbs with cheese and remaining 2 Tbsp. oil; season with salt and pepper. Top onions with squash (this can be a single layer or two or three layers) and breadcrumb mixture. Bake at 350° until squash is tender and breadcrumbs are golden brown, 20–25 minutes. Note: I am still getting used to my oven and my new oven thermometer, which doesn’t seem to be reliable. Both times I baked this, the oven was probably more at 400ºF or even 450ºF for parts of the baking time. So, if you know your oven, I suggest starting at 400ºF and checking the gratin after 15 minutes. If the gratin is looking too brown, turn the oven down to 375ºF or 350ºF; if it’s looking ok, just keep the oven as it is.

Meatless Monday: summer squash gratin, Suzanne Goin’s slow-cooked kale with white beans and Pecorino, peasant bread, and a wedge of Drunken Goat.

Meatless Monday

Finally: I found this white Pyrex gem at a flea market last weekend. Similar in size to the Pyrex #322, the Pyrex #441 makes a perfectly round little boule of bread. It has been hard these past few days not engaging in any eBay bidding wars
peasant bread


  1. says

    So much goodness here!! I love your Meatless Monday menu and wish that was all going to materialize on my table tonight so I could dig it (it is not going to happen — too much happening tonight to cook :( ). Wow! Yum.

    I also have been dreaming about a Baking Steel of my own almost non-stop since reading your first post about it. I am saving my $$$ and canNOT wait. Congratulations on being their pizza blogger — they could not have a better gal for the job! I will excitedly read along! I am such a pizza fan and always chasing that best-ever homemade pie. Happy to experiment, right? :) Last night I went to my brother’s house (he is 19 and always hungry) and made pizzas for us for dinner, for leftovers, and also froze some calzones for future dinners. He was in a total carb coma, clearly he does not cook like ever — his empty fridge was just the saddest sight. Even though we had no stone or steel, just homemade pesto and onions I over-caramelized on his super-hot stove, the pizzas were delicious and brought us together. I love it.

    I’m rambling! This gratin is so simple and beautiful, we have lots of friends gifting squashes to us these days so I can’t wait to give it a try.

    • says

      Sophie, your brother is a lucky guy! I am sure he knows so. There is nothing like homemade pizza, right? You MUST get a Steel! Rumor has it that they might doing a giveaway on Facebook soon. I’ll be sure to keep you posted. I have been dying to make calzones, actually on the baking steel — I wonder if it will work? Any tips on making calzones? I think this could be really fun.

      • says

        Thanks for the heads up on the Facebook giveaway! Exciting! I do calzones pretty much exactly like pizzas, I don’t see why the high heat and baking steel wouldn’t do wonderfully for them! My only tip is always slicing a couple vents in the top of the dough before baking…. then the sauce isn’t steaming the ingredients and I’m not cutting into a weepy, wet calzone. I try to steer away from fresh mozz in calzones for the same reason, it releases quite a bit of moisture. Good luck :)

  2. says

    am still having difficulty accessing your recipes–great pictures but i cant use up that amount of ink–how does one simply get a printable recipe? It used to be so easy!

    • says

      Oh no! ok, after you click on the “print” icon, the recipe should open into a new window. On the left side of the screen, there should be a button that says “remove images.” Click on that. And then, to remove any paragraphs of text that you don’t want, just hover your mouse over the body of text and click — that will delete it. I hope that helps! Sorry about this :(

  3. Anne Murphy says

    made this tonight along w/ Ina’s turkey meatloaf. It was delicious! Also made a 2nd batch of muesli – the best. Thanks for being 100% spot on!

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