Yellow summer squash casserole is a classic southern side dish. My father grew up in Florida eating this dish, and I grew up eating it at my house in Maine. We had a freezer in the basement and when the yellow crookneck and straightneck plants are cranking out the squashes like nobody’s business in July and August, my parents would cube, blanch, and freeze the squash so that we could enjoy this dish throughout the long Maine winter. At least that’s how I remember it. My father says they sooner or later figured out that summer squash doesn’t freeze very well. Then he only made this casserole in the summer.
Jump to RecipeToday my father, Stephen, writes, “I have served this squash casserole not only to my family but to a variety of guests, and it is universally loved. Once they eat it, they always want to have the recipe!”
Why It Works
This squash casserole is a kids’ favorite because of all the cheese and the crunchy, buttery bread crumbs, but I’ve enjoyed it, maybe for evolving reasons, from toddlerhood to middle age. I’m not a huge fan of summer squash, but there’s something magical here. Admittedly, you can take just about anything and surround it with butter, cheese, and bread crumbs and it will taste good.
But this isn’t an example of hiding vegetable flavor amid other flavors. Instead, what’s good about the flavor of summer squash is emphasized and amped up by the similar sharp and nutty flavors in the dairy products and toasty crumbs. The choice of herb to include changes the squash casserole, and I can’t predict which you’ll like best. Dill vs. thyme makes a difference: dill gives a softer, sweeter, grassy flavor and thyme pushes the taste and aroma in a more earthy and herbal direction.
What I Changed to Choose the Best Produce—and to Use Up Leftovers
I’m a big believer in working with what I’ve got and what’s in season, and that’s what I did when putting together this squash casserole for the blog. It’s January, and I was inspired to cook this dish now by some very fresh-looking organically-grown summer squashes from Florida, in season at the grocery store. Some of the yellow squashes looked a little overgrown to me, while the zucchini looked just perfect. So, diverging from anything my dad ever did, I went ahead and prepared this with some zucchini mixed in. That’s why you’ll see green among the toasty browns and yellows in these photos.
Also due to it being January, I had in pantry half a bag of bread-based stuffing mix (good ol’ Pepperidge Farm brand), left to sit since Thanksgiving. This product is essentially spiced and salted bread crumbs not quite yet in crumb form, so I crushed it up and used it in the dish. It’s a delicious variation, though the sage and rosemary flavors in most stuffing mixes will fight a bit with any fresh herbs that you include.
Cheesy Squash Casserole Recipe Notes
This is an easy recipe and very little can go wrong. But here are three quick tips to keep in mind as you prepare this recipe for the first time.
- Steam the cubed squash until it’s truly soft. If you like some crunch in your cooked fresh vegetables like I do, it goes against instinct to cook a summer squash until it’s soft, but that’s what you’ve got to do. A fork or knife should go through each cube easily.
- Dry the steamed squash well, you don’t want a watery casserole. You might even try pressing it a little with a kitchen towel.
- My father cooks this dish in two pie pans. He explains, “you can use a single larger baking pan, but it’s best not to heap the squash mixture more than a couple of inches high.”
In my house I am usually just cooking for two people, so I reduced the recipe to fit perfectly in a 10-inch cast iron pan.
My Father’s Cheesy Squash Casserole
Ingredients
- 3 pounds summer squash like yellow crookneck, or any shape/color of summer squash.
- 2 Tbsp oil or butter
- 1 onion, large
- ½ cup grated parmesan cheese
- ½ cup grated cheddar cheese
- ½ cup bread crumbs or crushed poultry stuffing mix, or one toasted bread slice cut up small
- 2 Tbsp fresh dill, chopped or 2 tsp fresh thyme, or half the amount of dried herbs
- ½ tsp pepper, black or white
- ¾ tsp salt
Instructions
- No need to peel the squash if it's fresh. Cut squash into 1 or 2-inch cubes and steam until tender.
- Preheat oven to 400°.
- Meanwhile, chop up the onion and sauté it in half the butter, olive oil, or other preferred oil in a large pan until the onion is fully cooked, even beginning to caramelize. Set aside the pan.
- Drain the steamed squash completely and stir it into the onions. Use a potato masher to crush up the squash into the onion mixture. You can mash it completely if you prefer, but if you leave it only partially mashed it will add more texture to the dish.
- Stir in the salt, pepper, and fresh or dried herbs (see note above recipe). Stir in the beaten egg.
- Mix together the cheeses and and bread crumbs and stir in all except 1/2 cup.
- Wipe a little butter or oil around two pie pans and pour the squash mixture into them.
- Take the remaining Tbsp of butter or a little oil and spread it across the squash mixture, then sprinkle the rest of the cheese and bread-crumb mixture around the top.
- Bake for about 30 minutes. You are looking for the top of the mixture to start showing a nice crusty brown, and then you know it's done. If that's not happening after 30 minutes or so, you can put it under the broiler to get that nice browning, but watch carefully; it happens quickly!