This Gluten Free Summer Squash Casserole is one of those recipes that I look forward to making every single summer when the garden is overflowing with zucchini and yellow squash and I need a delicious way to use it all up. It is rich, creamy, and packed with sharp cheddar cheese in the most comforting and satisfying baked side dish that disappears fast at any dinner table or potluck.
The combination of sour cream, mayonnaise, eggs, and cheese creates the most incredibly creamy filling and the gluten free bread crumb topping gets beautifully golden and crunchy under the broiler for the perfect finish.
The most important thing to know about this recipe is that you need to saute the squash and zucchini on the stovetop before baking. This step cooks out a lot of the moisture from the vegetables which is what keeps your casserole from getting watery. Do not skip it.
After that the rest of the recipe comes together quickly and the oven does all the work. This is genuinely one of my favorite summer side dishes and I think once you make it you are going to feel the same way.
If you are looking for more zucchini recipes try my Gluten Free Zucchini Squash and Corn Casserole, my Air Fryer Roasted Zucchini Squash, my Baked Kale and Zucchini Pilaf or my Easy Gluten Free Zucchini Brownies.
You can find all of my side dish recipes here: Gluten Free Side Dish Recipes
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Instructions
Preheat your oven to 350 degrees.
In an oven safe pan or cast iron skillet on medium heat add butter and allow to melt. Add the diced onions and cook until they're almost translucent. Add the minced garlic and cook 1-2 minutes more.
Add the diced yellow squash and zucchini to the onion mixture. Saute on medium heat until the squash starts to soften and the onions are completely translucent.
Add the eggs to the skillet and mix around until they are creamy and mixed into the vegetables. Add 1 cup of cheddar cheese, sour cream, mayonnaise, salt, pepper and 1 cup of gluten free bread crumbs. Stir thoroughly until everything is mixed together.
This mixture will be very thick and almost paste like. This will allow for the squash to continue to cook down in the oven and release water.
Top the mixture with the other ½ cup of cheddar cheese and ½ cup of gluten free bread crumbs.
Bake at 350 degrees for 45-50 minutes. The edges will be bubbling, the cheese will be melted and the top will be slightly browned when the casserole is done.
At this point, I like to turn my broiler on high and broil the casserole for 1-2 minutes. This will brown the top and give it a bit of crunch. Watch the casserole very closely as the browning will happen quickly.
Supplies
Storage
After the casserole has cooled completely store in an air tight container in the refrigerator for up to 5 days.
Frequently Asked Questions
This recipe has gluten free bread crumbs or rice crumbs in it for a thickener. After cooking the squash on the stovetop there is still a lot of liquid that hasn't evaporated you can add a bit more bread crumbs, but remember, that more moisture will evaporate as you bake this dish.
It's really important not to skip the step of cooking the squash and zucchini on the stovetop before adding the rest of the ingredients and baking. Cooking down the vegetables will evaporate off some of the moisture.
Then you will add the cheese, sour cream, mayonnaise, eggs, seasoning and bread crumbs. After adding these the casserole will be almost paste like and very thick. This is perfect because as the squash and zucchini continue to cook down and release water in the oven you will be left with a super creamy hot dish.
The edges will be bubbling and then cheese will be completely melted on top. The top will just be starting to brown a bit. I like to turn the broiler on high and finish browning the top of the casserole to give this dish a bit of crunch on top at this point.
More Recipes You Might Enjoy
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Gluten Free Summer Squash Casserole
- Total Time: 1 hour 15 minutes
- Yield: 8 servings 1x
- Diet: Gluten Free
Description
This Gluten Free Summer Squash Casserole is a rich, creamy, and cheesy baked side dish made with fresh zucchini and yellow squash, sharp cheddar cheese, sour cream, and gluten free bread crumbs for the most delicious and satisfying summer vegetable casserole you will ever make. The squash is sauteed with butter, onion, and garlic before baking which prevents a watery casserole and creates incredible depth of flavor with a beautifully golden and crunchy bread crumb topping. Naturally gluten free and perfect for summer dinners, potlucks, and using up garden zucchini and yellow squash all season long!
Ingredients
- 1 pound Yellow Squash, seeds removed and cut into ½ inch chunks
- 1 pound Zucchini, seeds removed and cut into ½ inch chunks
- 2 Tbsp. Unsalted Butter
- 1 medium Yellow Onion, diced
- 1 Tbsp. Minced Garlic
- 1 ½ cups Cheddar Cheese, grated
- ½ cup Sour Cream
- ¼ cup Mayonnaise
- 2 large Eggs, beaten
- 1 tsp. Sea Salt
- 1 tsp. Ground Black Pepper
- 1 ½ cups Gluten Free Bread Crumbs
Instructions
Preheat your oven to 350 degrees.
In an oven safe pan or cast iron skillet on medium heat add butter and allow to melt. Add the diced onions and cook until they're almost translucent. Add the minced garlic and cook 1-2 minutes more.
Add the diced yellow squash and zucchini to the onion mixture. Saute on medium heat until the squash starts to soften and the onions are completely translucent.
Add the eggs to the skillet and mix around until they are creamy and mixed into the vegetables. Add 1 cup of cheddar cheese, sour cream, mayonnaise, salt, pepper and 1 cup of gluten free bread crumbs. Stir thoroughly until everything is mixed together.
This mixture will be very thick and almost paste like. This will allow for the squash to continue to cook down in the oven and release water.
Top the mixture with the other ½ cup of cheddar cheese and ½ cup of gluten free bread crumbs.
Bake at 350 degrees for 45-50 minutes. The edges will be bubbling, the cheese will be melted and the top will be slightly browned when the casserole is done.
At this point, I like to turn my broiler on high and broil the casserole for 1-2 minutes. This will brown the top and give it a bit of crunch. Watch the casserole very closely as the browning will happen quickly.
- Prep Time: 30 minutes
- Cook Time: 45 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: American
If you made this Gluten Free Summer Squash Casserole I would love to hear what you thought! Please leave a star rating and a comment below. This is one of my favorite summer side dish recipes and I hope it becomes one of yours too!
Top Tip
Do not skip the step of sauteing the squash and zucchini on the stovetop before adding the remaining ingredients and baking. This is the most important step in the entire recipe. Summer squash holds a tremendous amount of water and cooking it down first allows that moisture to evaporate before the casserole goes into the oven. If you skip this step your casserole will be watery and soupy rather than creamy and set. Cook the squash until it has softened and the onions are completely translucent before moving on.
Jennifer says
This looks so good Elaine!!
smallfarmbiglife says
Thanks Jennifer! I hope you enjoy it. ~Elaine