Summer Squash Casserole is a classic savory southern casserole dish that uses fresh yellow squash, and is easy to make. It is full of cheesy goodness, and has a crispy panko topping. This makes a great side dish for a dinner or a yummy dish for a dinner party.
What's the difference between yellow squash and zucchini?
There really aren't huge differences between the two. Zucchini, or courgettes, are dark green with soft white flesh and have more seeds than yellow squash. They are typically straight, and both are members of the squash family.
Yellow squash is of course yellow in color but often have a crooked neck. Both taste very much the same, and are typically prepared in the same ways. They can be combined in recipes or swapped out if you have one but not the other. Both can be found growing in the wild, and usually are abundant in home gardens.
How to buy and store yellow squash
You want to look for small, firm squash that don't look like they've been beat up. You want them to be free of blemishes or brown spots. Avoid large squash that feel soft, and feel to light as they may have dried out.
Store in an airtight bag in the refrigerator for up to one week. They may last longer but they are delicate so it depends a bit on the produce. To freeze, slice, blanche, and then store in plastic freezer bags for up to three months.
You'll need a few easy to find ingredients for this recipe.
- Yellow squash - look for produce that is about the same in size, and then cut into uniform sizes. You can mix and match with zucchini or replace it with zucchini entirely since both can be used interchangeably. Do not peel the squash.
- Onion - I like to use a milder Vidalia onion, but regular yellow onions will work just fine. Dice finely, and set aside.
- Garlic - minced.
- Eggs, mayonnaise, and milk - this will combine to form the base of your filling.
- Colby Jack, Mozzarella, and Parmesan Cheese - I really love the flavor result of combining different cheese. You can choose just one or combine any of your favorite shredded cheeses for this dish.
- Panko bread crumbs and more Parmesan cheese - I use seasoned Panko, and mix with more cheese to get my crusty topping. You can swap out regular bread crumbs, crushed crackers, or even crushed potato chips.
Start by slicing about six yellow crookneck summer squash into roughly ¼-inch slices. Dice one large onion as well.
For this dish we will need to saute the sliced summer squash, diced onions, and some minced garlic for a few minutes until slightly softened but still firm. They should cook about 5-7 minutes, and then they will need to be strained in a colander to remove excess moisture.
Beat two eggs in a medium bowl. Add the mayonnaise, milk, Colby Jack Cheese, Mozzarella Cheese, and Parmesan cheese. Salt and pepper to taste. Stir until well combined.
Grease a 4-quart or medium size casserole dish, and put drained yellow squash mixture in pan. Mix in the cheese mixture very well. Preheat the oven to 400-degrees.
Combine together the panko breadcrumbs and the additional Parmesan cheese. Cover the top of the casserole with the topping. Bake for 30 minutes or until the top has browned. Enjoy you Delicious Summer Squash Casserole!
Can I make this ahead or freeze this?
Yes, you can make this a day ahead. It can be be stored once cooked for up to one week in an airtight container. You can also just assemble up to the point of baking, and cook the next day.
Store in the refrigerator once it's cooled and then warm in a 200-degree oven for about thirty minutes or until desired serving temperature is reached. It helps if you have time to set out on the counter to reheat for about 45 minutes prior to putting in the oven. You can freeze this for up to 3 to 4 months.
Southern Summer Squash Casserole Recipe
- 6 large yellow squash sliced, ¼ inch thick
- 1 large onion diced
- 1 tablespoon garlic minced
- 2 eggs beaten
- ½ cup mayonaisse
- ½ cup milk
- 1 cup Colby Jack Cheese shredded
- 1 cup Mozzarella Cheese shredded
- ¼ cup Parmesan Cheese shredded
- Salt and Pepper to taste
- ¾ cup Panko breadcrumbs
- ¼ cup Parmesan Cheese shredded
- Slice the yellow summer squash into roughly ¼-inch slices, dice the onion. Preheat a medium pan. Add oil or butter to the pan for cooking Add the yellow squash, onions, and garlic. Salt and pepper to taste. Cook about 5 to 7 minutes until slightly softened but still firm. Remove to a colander to drain excess liquid from squash mixture.
- Combine in a bowl the eggs, mayonnaise, milk, and cheese. Salt and pepper to taste.
- Grease your casserole dish. Add the squash and cheese mixture together into the casserole dish then mix well.
- Combine the panko breadcrumbs, and additional Parmesan cheese. Top the squash casserole evenly with the topping.
- Bake in a preheated 400-degree oven for thirty minutes until top is browned.
- Serve immediately. May be stored for up to one week in an airtight container.