A Summery Gratin Worth Turning On the Oven For

August 24, 2017

My brother-in-law Tim arrived Friday evening with his four children, a case of beer, and a bag of vegetables—the fruits of his, as he described, “backyard CSA”: a half dozen plump, weighty Cherokee Purple tomatoes, two dirt-shrouded onions with straggly greens intact, and four one-pound-plus summer squash clubs. Um, thanks? At the moment, it was hard to say who should be thanking who.

Turn your summer uglies into something tasty. Photo by Alexandra Stafford

It turns out, I would be thanking Tim. His children, moments after their arrival, disappeared, swallowing mine in their wake. The beer, shortly thereafter, went down easy, dissolving (briefly) all the worries in the world. The tomatoes, the next day, floated atop cream cheese-smeared bagels. The squash, two days later, baked into this gratin, one of my favorite summer meals.

As you can gather, I had my doubts about the squash—a pass down the mandoline revealed airy centers and a host of big, uninviting seeds. After a brief roasting, however, my concerns faded. The golden slices tasted sweet without a trace of bitterness.

Roast 'em real good. Photo by Alexandra Stafford

Over the years, I’ve made many variations of this gratin—it’s simple: roasted vegetables + grated parmesan cheese + red bell pepper-tomato sauce + fresh bread crumb topping. It’s a foolproof formula. A simple green salad is all it needs.

Well, how did we get here? (Keep reading!) Photo by Alexandra Stafford

Note: This is not a weeknight meal. If you roast many pounds of vegetables, you will need many sheet pans. To make the sauce, you need a pot. If you, as I, like grinding bread for crumbs and blocks of cheese in a food processor, count on dirtying that, too. That said, this dish will comfortably feed six people, and it’s an answer to the question asked often this time of year: What to do with all this darn squash? If you dedicate time to this gratin, you’ll no longer spend time conducting stealth missions, dropping cases of zucchini on neighbors’ doorsteps or into strangers’ unlocked cars. Gather your burdensome, seedy, home-grown baseball bats. They’re all welcome here.

A Layer-by-Layer Guide

Roasted vegetables: I’ve used eggplant, zucchini, summer squash and a mix of all three though I imagine any number of vegetables would work well here. The key is in the roasting, which draws out the moisture of the vegetables, ensuring the flavor of the gratin will be sweet and concentrated, and the texture, not watery. You can roast as many or as little vegetables as you wish. I used a 9x13-inch baking dish here, but in the past, when I’ve roasted fewer vegetables, I’ve used an 8- or 9-inch square or circle baking dish.

Ready to roast and blister. Photo by Alexandra Stafford

Red-pepper tomato sauce: This is an old Michael Chiarello recipe from The Tra Vigne Cookbook, and it’s one of my all-time favorite sauces to make, this time of year especially: Throw chopped tomatoes and red peppers (about 2 cups each) into a pot with water and salt—no oil or butter (yet). Simmer until the liquid nearly evaporates and the vegetables thicken, then purée them with basil and butter or olive oil. Toss the sauce with pasta, serve it as a dip, or layer it, as here, with vegetables (or noodles). It’s so good.

It's in pre-processor mode. Photo by Alexandra Stafford

Grated Parmesan: For quick grating, use the shredder attachment of your food processor. Then, before cleaning it, use the main blade to grind the bread for the topping.

Roasted vegetables + grated cheese + red sauce + bread crumb topping. It’s a foolproof formula.
Cheese and bread crumbs? Good to go. Photo by Alexandra Stafford

Bread crumb topping: Here, the fresh bread crumbs are tossed simply with olive oil, salt, and grated parmesan, but you could season them further with herbs such as thyme or parsley or with minced garlic or, for a kick, crushed red pepper flakes. The fresh crumbs bake into a golden layer, melding into the roasted vegetables beneath them. This same mix can be spread over pasta, beans, meat, other vegetables—it’s irresistible.

What do you like to put in your gratin? Let us know in the comments!

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    Nikkitha Bakshani
I write the blog alexandra's kitchen, a place for mostly simple, sometimes fussy, and always seasonal recipes. My cookbook, Bread Toast Crumbs is available everywhere books are sold.


Mary-Gay September 3, 2017
A little labor-intensive (lots of sheet pans involved), but definitely worth it!! Sadly, family dairy issues have pushed parmesan out of my cheese drawer, but even with a vegan substitute ( I have had great success with http://thismessisours.com/recipes/how-to-make-vegan-parmesan-cheese/), it was awesome. Thanks for another keeper, Alexandra!
Alexandra S. September 3, 2017
So happy to hear this! And yes: so many sheet pans! Wish there were a way to avoid this. Thanks for the link to the vegan parm cheese — I've got to try it!
Tim August 29, 2017
This guy Tim sounds like a cool guy. Is he any good at ping pong?
Alexandra S. August 29, 2017
Typically he CRUSHES his serves, but the family consensus is that he could work on his back spin returns.
Lazyretirementgirl August 25, 2017
Boy, does this hit the spot! Especially since I always have bread crumbs in the freezer and grated Parmesan in the fridge ( don't judge), making this not really so hard after all.
gandalf August 24, 2017
Regarding the tomato-pepper sauce: When dicing the tomatoes, do you peel them? Do you use the seeds/jelly, or remove that? (I presume that you core the tomatoes, also.)

Also, no need to pollute the Cherokee Purples with a bagel/cream cheese; it's hard to beat plain thick slices on a plate with a bit of salt! :>)
Alexandra S. August 24, 2017
Hey! No seeding, no peeling — it's so easy! I just cut straight down around the core, and chop up those slices roughly. I use the lower half of the core that isn't too tough. It's one of my favorite sauces! Definitely rely on the visual cues as opposed to the 25 minute timeline — you want the mixture to get stewy and thick and begin sticking to the pot before you purée it with the butter and basil.
gandalf August 24, 2017
Thank you!
Liza September 3, 2017
How much water in the sauce?
Alexandra S. September 3, 2017
1/2 cup to start — it's not listed in the ingredients, but it's in the instructions: here's the full recipe: https://food52.com/recipes/72761-summer-squash-gratin
Nikkitha B. August 24, 2017
I don't think this will get to 5 other people once I get into it! Making this recipe as soon as I move into my new apartment :).
Alexandra S. August 24, 2017
Haha, I love it :) :) :) Do it!!