Say it with me now: “Comfort food is not just for cooler weather!” A healthy riff on a classic, Zucchini Casserole makes the most of seasonal squash. Crispy on the outside, gooey on the inside, this baked dish balances buttery creaminess with bright herbs for a summer supper sensation! With gluten free and keto options.
I don’t write a lot about the <<gestures widely>> current global news, because it *hopefully* has a shelf life and my blog *hopefully* doesn’t. But this past winter, after almost 10 months under lock and key, I knew I needed something to look forward to, so I started my summer reading early.
Interestingly enough, my literary adventures centered around one region – New England. Let’s just call it what it is – I was devouring chick lit beach reads in the middle of a winter lockdown.
I kept noticing, across books and genres, that there were some surprisingly evocative references to cuisine. And that it was talked about with the same passion and nostalgia that you’d expect to find in more, let’s call them, food-centric regions.
Not that I ever assumed our countrymen to the north didn’t like food! Just that, you know, puritanical roots run deep and it’s always seemed a bit stoic to this particular outsider from New Jersey who now lives in the “south.” But no! Reader, I was wrong for days!
I started digging and stumbled upon an absolute gem of a cookbook by Sarah Leah Chase – the New England Open House Cookbook – and have been going down an almost life-changing rabbit hole ever since. Not only do I have a fairly extensive (and probably too expensive) trip planned on paper, but I’m spending more time looking into my own regional food roots. Of course, I’ve also been paying homage in my own kitchen by trying her incredible recipes.
This zucchini casserole recipe is inspired by her version of the classic casserole that frankly, I never knew existed. But I and my husband – who I literally had to chase off from the pan with a wooden spoon – are eternally grateful for her creativity, insight, and liberal use of salt and fat.
How to Make Zucchini Casserole
Zucchini Casserole is a showstopper of a side dish that is worth every swirl of the skillet and minute in the oven on a hot summer day. Fresh summer zucchini and yellow squash get sauteed and baked into a comforting concoction with bright herbs, tangy tomatoes, gooey cheese, and buttery breadcrumbs. Be forewarned – consider making a double batch! Second and third helpings are a certainty.
For a condensed post, click to view the web story for this recipe!
- PREP. Heat the oven to 350°F and grease a 9” x 13” casserole dish with olive oil spray or butter.
- MAKING TOPPING. Combine breadcrumbs and butter until the breadcrumbs are evenly moistened.
- ONIONS & GARLIC. Saute onions in butter until soft; add plenty of fresh garlic at the end and cook until fragrant.
- ZUCCHINI AND SQUASH. Add zucchini and squash to the pan. Cook until their liquids release and cook off completely, about 15 minutes.
- TOMATOES. Add diced tomatoes (including the canning liquid), then season. Simmer for 5 minutes to cook off any remaining liquid.
- LAYER CASSEROLE. Scrape vegetable mixture into the baking dish. Sprinkle with cheese, then add the breadcrumb topping.
- BAKE. Bake uncovered for 30 minutes, until golden and bubbling.
- GARNISH AND SERVE. Rest 5 minutes, then liberally garnish with fresh basil and serve.
- Thoroughly grease your baking dish. Olive oil will keep it healthier, but if you can spare the calories, butter absolutely makes it better.
- Important: saute the zucchini and squash all the way through, until visible liquids have evaporated, at least 15 minutes. This will prevent your casserole from being watery.
- Don’t be shy with your toppings or your cheese. This is a great recipe to make “your way” – suggestions below.
Is it Watery?
Nope! The water cooks out in the sautéing stage, as long as you cook long enough – 15 minutes minimum, depending on your squash.
Make it Your Way
HERBS: Top with fresh herbs like basil, thyme, or parsley. The herbs really enhance the flavor.
CHEESE: If you’re not a fan of sharp cheddar cheese, try mozzarella, smoked mozzarella, or medium cheddar. Feel free to substitute up to a quarter cup of one of these softer cheeses for shredded parmesan for more of a bite.
MAKE IT GLUTEN FREE: use gluten free breadcrumbs.
MAKE IT KETO/LOW CARB: substitute coarse almond meal for the panko breadcrumbs to make the crispy topping.
Frequently asked questions
Store leftovers in a sealed container in the fridge for up to 2 days. Reheat at 350°F until warmed through. Don’t freeze.
This dish can be served as a main course or a side dish, hot from the oven or warm/room temperature.
More Healthy Summer Sides: Comfort Food Edition
- Gluten Free Fried Green Tomatoes
- Green Beans with Bacon and Garlic
- Classic Italian Potato Salad
- Broccoli Bacon Salad
- Bacon Coleslaw
Did you make this zucchini casserole? I’d love to know how it turned out! Leave a comment and a rating below.
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- 9×13 Casserole Dish
- 6 tbsp butter, divided
- 1 c panko breadcrumbs, or almond meal, see notes
- 1 medium vidalia onion, diced to ½”
- 3 clove garlic, minced
- 3 medium zucchini, about 1.5 pound, diced into 1” pieces
- 1 medium yellow squash, about ½ pound, diced into 1” pieces
- 1 14-oz can diced tomatoes, fire roasted preferred
- 1 tsp dried basil
- ½ tsp dried thyme
- 1¼ tsp kosher salt
- ½ tsp ground pepper
- 4 oz 1.5 cups sharp cheddar, shredded
- fresh chopped basil, for garnish
- Heat oven to 350°F. Mist a 9” x 13” casserole dish with olive oil cooking spray; alternatively rub with additional softened butter.
- Melt 2 tbsp butter. Add the melted butter to the breadcrumbs and mix until the breadcrumbs are evenly moistened. Set aside.
- Heat the remaining 4 tbsp butter in a 12” skillet over medium high heat until the butter melts then foams. Add the onion, toss to coat in the fat, and saute, stirring occasionally, until the onion softens, 6-7 minutes. Add the garlic and saute, stirring continuously, until fragrant, about 1 minute.
- Add the zucchini and squash to the pan. Saute, stirring occasionally, until the zucchini and squash release their liquids, the liquid cooks off, and the vegetables are tender, about 15 minutes.
- Add the diced tomatoes (including the canning liquid), basil, thyme, salt, and pepper. Stir to combine, then bring the liquid to a simmer; adjust the heat to maintain a steady simmer and cook for 5 minutes.
- Scrape the mixture into the prepared casserole dish. Sprinkle the shredded cheese over the vegetable mixture, then sprinkle the breadcrumbs evenly over the casserole.
- Transfer to the oven and bake for 30 minutes, until the cheese is melted, the topping is golden brown, and the casserole is bubbling. Rest five minutes, then garnish with fresh basil and serve hot or warm.