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This Amazing Yellow Squash Casserole is a healthy remake of an old Thomas family Thanksgiving side dish favorite that I remember my aunt Renee making! Ryan and I both loved it, and I don’t think anyone is going to be able to tell that it’s healthy. THM S and low carb or not, this yellow squash casserole is just plain delicious. The cracker/fried onion/cheese topping is the “icing on the cake.”
PS – I just posted a brand new Deviled Turkey & Stuffing recipe, so CLICK HERE to see that!
Since a lot of traditional Thanksgiving casseroles use those French fried onions from a can as a crunchy, savory topping, I decided to base the top of this casserole off of my Southwestern Meatloaf topping made from caramelized onions and cheddar cheese. Cooking the onions down before baking on top of the casserole lets them dry out a little in the oven and get even more flavorful. Combined with cheddar cheese, Parmesan cheese, and some Ryvita or Wasa cracker crumbs, the topping becomes this golden brown, textured amazingness that perfectly complements the cheesy squash layer.
This squash casserole is really easy to make even though you do have to sauté the squash and onions before assembling and baking the casserole. The extra steps are worth the work, though, and don’t try tell me your normal, unhealthy Thanksgiving favorites aren’t a little more involved than your regular fare. 😉 This casserole is also heavier in calories than I usually make, but again – Thanksgiving.
Some notes on the ingredients I used:
- I bought fresh yellow squash from Kroger, my local grocery store, to make this casserole, and I recommend using fresh for the best result. If you have frozen squash from your garden in the freezer you’re welcome to thaw it and try to use it, but that’ll be a bit of an experiment. Frozen squash is already somewhat broken down because of the freezing and thawing process, so you may not need to sauté it before adding it to the casserole. However, I’m not sure how much liquid you should drain off. The casserole does need some liquid, but not TOO much. You’ll just have to try it and use your best judgement. Or use fresh squash. 😉
- Substitute for the oat fiber at your own risk. Oat fiber is a really fine, dry flour that mimics white flour to thicken sauces better than any other low-carb flour I’ve tried. It’s not gritty or slimy. Not all brands are created equally; I prefer LifeSource brand (CLICK HERE).
- I use the regular mild yellow curry powder available from most US grocery stores and Walmart. You don’t really taste it overtly in this casserole, but it does add a nice flavor that really complements the squash so I don’t recommend leaving it out. (It also contributes to a nice yellow color.)
- I use Better than Bouillon chicken base from Walmart. It’s high quality and tastes great, and the added sugar is minimal per serving, especially when spread out over a whole casserole!
- Ryvita crackers are similar to Wasa crackers but a tiny bit lower in carbs. You can use Light Rye Wasa crackers if that’s what you have (available at many local grocery stores). 3 Ryvita crackers contain 15 grams of net carbs, or 1 net carb per serving. You could try omitting the crackers for a gluten-free option or replace with some crushed pork rinds.
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As always, check out the Notes section of the recipe for extra info. Check out the links in and below the recipe to see the products I use and recommend. Some of the links included in the recipe and blog post are affiliate links, which means that if you make purchases through these links, I make a small commission (but your price doesn’t change).
Do you have a copy of my new cookbook, Convenient Food, yet? It was just released the end of October and would make a terrific Christmas gift for yourself or someone you love! Both Necessary Food and Convenient Food contain about 400 low-glycemic recipes each, separated by carbs and fats and free of refined sugar and flour (like all the recipes here on my website). I grew up on my momma’s good cooking, and the recipes in these books are mostly just old family favorites made healthy! Now that I’m married, I’m gravitating even more toward quick and easy, and my newest cookbook definitely reflects that! CLICK HERE to check out my cookbooks in more detail and purchase.

- 2 teaspoons salted butter
- 9 cups sliced yellow summer squash
- 1 tablespoon dried minced onion
- -
- 1 ½ cups shredded cheddar cheese
- 1 cup low-fat sour cream
- ½ cup mayonnaise
- ⅓ cup unsweetened almond or cashew milk (plain, not vanilla flavored)
- 3 tablespoons oat fiber (use gluten free if necessary)
- 1 teaspoon each curry powder, onion powder, black pepper
- 1 teaspoon chicken bouillon
- ½ teaspoon salt
- 2 teaspoons salted butter
- 1 large onion (sliced)
- -
- 1 cup shredded cheddar cheese
- ½ cup grated Parmesan cheese (the green can kind)
- 3 crushed Light Rye Ryvita crackers (omit for gluten free)
- Sauté the squash and dried minced onion in the butter until completely tender and starting to fall apart. (I cover the skillet to speed up the process. It’s OK to have some liquid in the casserole, so don’t drain the squash before adding it to the rest of the ingredients.)
- While the squash is cooking, stir the second section of ingredients together in a mixing bowl.
- Add the hot squash when it is tender and mix everything together. Spread the mixture into a greased 9”x13” pan.
- To make the topping, sauté the sliced onion in the butter until tender and caramelized.
- Meanwhile mix the cheddar cheese, Parmesan cheese, and crackers crumbs together.
- When the onion is nice and brown, stir it into the cheese and cracker crumb mixture, then quickly spread the topping over the casserole before the cheese melts completely and sticks together.
- Bake the casserole (uncovered) at 350* for 30 minutes or until hot and bubbly and the topping is golden brown.
-Substitute for the oat fiber at your own risk. Oat fiber is a really fine, dry flour that mimics white flour to thicken sauces better than any other low-carb flour I’ve tried. It’s not gritty or slimy. Not all brands are created equally; I prefer LifeSource brand (CLICK HERE).
-I use the regular mild yellow curry powder available from most US grocery stores and Walmart.
-I use Better than Bouillon chicken base from Walmart.
-Ryvita crackers are similar to Wasa crackers but a tiny bit lower in carbs. You can use Light Rye Wasa crackers if that’s what you have (available at many local grocery stores). 3 Ryvita crackers contain 15 grams of net carbs, or 1 net carb per serving.
ALLERGEN NOTES: Use gluten-free oat fiber, gluten-free chicken bouillon, and omit the cracker crumbs or try substituting with crushed pork rinds for a gluten-free version. Use carton coconut milk for a nut-free version. (Most people with tree nut allergies can have coconut products, but confirm with your doctor first.)
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Hi, Briana!
I have been following the THM way of life for a year now. This recipe has become one of my favorites and I wanted to let you know! I especially love the topping! It is reminiscent of the unhealthy fried onions that you can get in a can–but better. I made it for Thanksgiving (2019) and my non-THM husband and his non-THM family loved it, too. As a matter of fact, he didn’t want me to share leftovers with them so he could have them all! Thank you for giving us this recipe!
Thank you so much for making it, Becky – and for letting me know how much y’all like it!
This is absolutely delicious. We had it tonight. I love the Curry taste. Yummy ? thanks for sharing. I actually used squash from our garden this past year that I cooked ahead and it was frozen. I did drain most of juice and left what would be a normal amount that I would have if cooking fresh.
What is considered ‘yellow squash’? Can I use an acorn squash?
Yellow summer squash – similar to zucchini, but yellow. (https://en.wikipedia.org/wiki/Summer_squash) They’re much softer than acorn squash. I’m afraid acorn squash would not work in this recipe due to the difference in texture.
This sounds yummy 🙂
How many squash made the 9 cups?
Thanks, Jen! My grocery store just had tiny little squash so I actually used quite a few…maybe 6-7…but they were tiny and not normal-sized at all.