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A very easy side, this Squash Casserole comes together quickly while you cook other things! Decadent, creamy and garlicky – this will be the star of any dinner!
Step by step photos and instructions below!
This Squash au Gratin was born from wanting a quick dinner, but nothing too crazy time-intensive (under 20 minutes). I had some chicken breasts, some green beans, and plenty of squash. Ta-da!
Cream, roasted garlic, fresh thyme and panko crumbs play important roles – taking it from your run of the mill sautéed squash, to “forget the chicken, gimme more of the veggies” I really am all about the side dishes!
To be clear, this is NOT exactly diet food. But we’re coming up to the holidays, so let’s let this one slide. Like Julia Child says “If you’re afraid of butter, use cream” I love that woman.
Frequently Asked Questions
The “Au Gratin” in the name simply means “a dish with a light browned crust of breadcrumbs or melted cheese”… so, basically, food of my dreams!
Don’t boil the squash, or it will release all it’s liquid. Just a light sauté so it should be cooked, but still have firmness to the bite.
Why you’ll love this recipe
- Made in a skillet, with no need to dirty another dish before baking.
- This is au gratin style, which basically is heaven on a plate.
- Easy to make. Seriously, no culinary degree needed.
I have included step by step photos and instructions, as well as tips and tricks in the post. If you’d rather skip all that, scoot right on down to the full recipe card located at the bottom of the post.
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About the skillet
Use any skillet that can go from stovetop to oven, no lid is needed. It does take some effort to get it out of the skillet in a pretty way, but if your family is like mine – they won’t care. If you’re not a food blogger who needs to take pics, you shouldn’t care either!
If your skillet isn’t ovenproof, no problem. Just cook in a regular skillet, then remove to a casserole dish or small baking dish (lightly greased) before topping.
The full list of ingredients and quantities is found in the printable recipe card below.
- Panko Breadcrumbs. These are Japanese style breadcrumbs are are light and crispy. You can find them in the same place at the store as regular breadcrumbs.
- Garlic Powder. This flavors up the topping.
- Fresh Thyme. You can use dried thyme if you need to.
- Parmesan Cheese. Grate this fresh, if you can. It melts way better than pre shredded cheese.
- Butter. I use salted butter.
- Squash. I use a mix of yellow summer squash and zucchini. Whatever I can find at the time, really.
- Roasted Garlic. See my easy recipe for how to roast garlic below. Raw garlic will be sharp and unpleasant so definitely take the time to roast the garlic. If you don’t want to, just add a teaspoon of garlic powder instead.
- Heavy Cream. Don’t use anything else instead. We need the thick cream to make the sauce work properly.
How to make this recipe
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The full list of ingredients, quantities and instructions can be found in the printable recipe card below.
Prepare the topping
Combine topping ingredients and set aside.
Preheat the oven to 450 degrees F.
For the vegetables
Heat a large skillet over medium heat, and add the tablespoons of butter, and melt.
Add the zucchini to the pan, season with salt and pepper and sauté for 3 minutes.
Add the chopped roasted garlic to the pan with the squash mixture, stir together, and cook for 1 min.
Pour the heavy cream into the pan, and stir together with the vegetables.
Bring to a simmer, and cook for 2 mins, or until the cream has reduced slightly.
Remove skillet from heat, and sprinkle the topping over the vegetables evenly.
Place skillet in the oven, cook for 4 mins, then switch to broil – and cook until the top is golden brown.
Remove skillet from oven, and let stand for 5-8 minutes, then serve.
Use cream for the sauce. Don’t use anything else, we need the thick cream to make the sauce work properly.
Do let it simmer gently, and don’t worry about how liquid-y it still is when you put it in the oven. Magic will happen. Promise.
Let it stand/rest after removing from the oven – this will help it to set, and be easy to scoop.
Any kind of squash can be used. I use both yellow squash and zucchini because they’re super pretty when combined!
Sub dried thyme in the gratin instead of fresh if you don’t have it.
Sub ritz crackers or another type of cracker crumbs mixed with melted butter if you don’t have panko breadcrumbs.
More delicious sides:
- Easy Scalloped Potatoes. There’s a video on this post showing how easy this is to make!
- Twice Baked Potatoes. A drool-worthy side dish, these Twice Baked Potatoes are SO good! Make a lot and freeze some for another day.
- Creamy Garlic Parmesan Risotto. Risotto in 17-25 minutes?! I’m in!
- Pan Roasted Brussels Sprouts. Roasted Brussels sprouts, paired with delicate shallots, salty bacon and a bit of parmesan – YES PLEASE
- Roasted Broccoli. The unsung hero of weeknight dinner sides. This easy recipe is hands-off and super delicious!
- Bacon Wrapped Green Beans. The BEST side for holidays! Fresh green bean bundles are easy to grab and soon to be family favorite!
- Grilled Zucchini. Perfectly Grilled Zucchini with a hint of lime, this easy recipe makes a great side dish and is super fast!
- Glazed Carrots. A simple side dish, using the sweetness of brown sugar combined with fresh rosemary. These Rosemary Glazed Carrots are great for holidays or just a regular Tuesday!
- Sauteed Green Beans. Garlic and shallots gently flavor these sautéed green beans making them a wonderful weeknight or holiday side dish!
- Red Lobster Biscuits. Soft, fluffy biscuits packed with cheddar cheese, and brushed with flavorful garlic butter after baking, these cheddar biscuits are dreamy!
- ALL SIDES
Squash Casserole (Au Gratin Style)
For the topping
Prepare the topping
- Combine topping ingredients and set aside.
For the vegetables
- Preheat the oven to 450F.
- Heat a large skillet over medium heat, and add the tablespoons of butter, and melt.
- Add the sliced squash to the pan, season with salt and pepper and sauté for 3 minutes.
- Add the chopped roasted garlic to the pan with the squash, stir together, and cook for 1 min.
- Pour the heavy cream into the pan, and stir together with the vegetables.
- Bring to a simmer, and cook for 2 mins, or until the cream has reduced slightly.
- Remove skillet from heat, and sprinkle the topping over the vegetables evenly.
- Place skillet in the oven, cook for 4 mins, then switch to broil – and cook until the top is golden brown.
- Remove skillet from oven, and let stand for 5-8 minutes, then serve.
Nutritional information is an estimate and provided to you as a courtesy. You should calculate the nutritional information with the actual ingredients used in your recipe using your preferred nutrition calculator.
Update: This recipe was originally published in May of 2017. It was republished with updated photos in June of 2022.