Easy Yellow Squash Casserole (One Pot)

Quick, easy yellow squash casserole recipe, homemade with simple ingredients in one pot in 30 minutes. Full of onions, cheese, herbs, Ritz topping.

Well, it's that time of year where your garden is overflowing with so many veggies that you don't know what to do. I have a solution: make casseroles! It's a great way to use all that squash without letting it go to waste. Plus, it's easy, delicious, and simple, just like my other casserole recipes: Chicken Broccoli Rice Casserole (One Pot), Cheesy Hashbrown Casserole (One Pan), Green Bean Casserole (One Pot), Meatball Casserole (One Pot), Easy Sweet Potato Casserole (One Pan), or Easy Frito Pie (Chili Pie Casserole).

How to make easy yellow squash casserole recipe from scratch?

1. Heat butter- In a large oven-safe pan.
2. Saute squash and onions- Until partially tender and set aside.
3. Add remaining ingredients mixture- This includes eggs, cheddar cheese, mozzarella cheese, milk, sour cream, salt, pepper, garlic powder, onion powder, Italian seasoning.
4. Spread mixture in pan- As evenly as possible.
5. Make topping- By combining breadcrumbs, Ritz crackers, butter.
6. Sprinkle- Over the squash mixture. 
7. Bake- Until top is golden brown.

What sides to serve with casserole?

This is a full meal on its own and I would only recommend a salad to complete it further, if necessary. Try this Easy Green Salad (One Bowl) or this Cucumber Radish Salad (One Bowl).

How do you keep squash casserole from getting watery?

Measure ingredients accurately. Also, make sure to sauté squash instead of boiling or steaming it to avoid adding additional water. If your casserole is too soggy after cooking, simply put back into the oven and bake uncovered to evaporate excess liquid. 

How do you thicken casserole?

Simply put the casserole back into the oven uncovered without any foil and bake until the excess liquid evaporates. Another option is to mix in some cornstarch into the squash mixture.

Do you peel squash before you cook it?

That depends on what type of squash is being used. For this recipe I use yellow squash, which, like zucchini, does not need to be peeled. Other squash, such as butternut, need to have the skins removed first.

Crispy casserole topping

This is the key piece to elevating this dish. The crunchy topping adds a textural dimension to balance the creamy veggie mixture. It's made my mixing together seasoned bread crumbs, Ritz crackers or any other savory crackers of your choice and butter.

Variations for creamy cheesy casserole

Spaghetti squash casserole- Simply substitute the round sliced yellow squash for spaghetti squash. Here is a post on How to Make Spagehtti Squash (Instant Pot) if you have never made it before.

Use butternut squash- This can be used instead of yellow squash. Be sure to peel the butternut before cooking. Cook time will be longer, because this is a harder squash.

Consider adding zucchini- Mix in some round zucchini slices to compliment the other flavors or you can substitute straight across for an all zucchini casserole. Both are delicious!

Add chicken- This is a great recipe to add some protein. I like to use leftover shredded or diced Rotisserie Chicken for a quick, easy, and delicious option. You can also use Shredded Chicken for added filling and flavor.

Add beef- You can also add diced Roast Beef, seasoned ground beef, or Shredded Beef for a more hearty meal.

Try other cheeses- I used a combination of cheddar and mozzarella but you can also add some parmesan, romano or Monterey Jack.

Tips and techniques

Use freshly shredded cheese- Because it melts better and will give you a better look and taste for your casserole. The reason being, the pre-shredded cheese has a powder on it to keep the shreds from sticking together. This changes the texture and melting qualities of the cheese.

Cream of mushroom soup vs. Sour cream- You can substitute one for the other, but the cream of mushroom will add a slightly different flavor, have small chunks, and may cause the casserole to be more mushy because it isn't as thick as sour cream. You can also try cream of chicken.

Adjust Italian seasoning- According to your preference. It can also be omitted if you are using herb seasoned crumbs for topping.

Cutting squash- Although you can cut the squash in chunks, it is best to cut them in thin, half circles, because it will cook faster and soak in more of the surrounding flavor without having large pieces to chew.

Use unsalted butter- And be sure to taste test food before adding more salt, because you don't want your dish to be so salty that no one can enjoy it!

Cook uncovered- Because using tinfoil to cover the pan will make the topping soggy and retain more liquid, making the casserole too soupy.

Pat the squash slices dry- With paper towels. This will get rid of extra moisture.

Shredded carrots are optional- But I like to add them for additional nutrition and I love the pop of color it gives the overall dish and subtle flavor.

Storage

Refrigerator- Leftovers can be stored in a sealed container in the fridge for up to 3 days. Keep in mind the crackers will no longer be crispy.

Freezer- Leftovers can be saved in freezer bags or sealed containers for up to 1 month. Before serving, fully thaw and reheat in oven.

Make ahead- Except tthe cracker topping, mix and spread all the ingredients in a casserole dish, cover, and place in the fridge 1 day in advance. Add the Ritz cracker topping just before baking.

More one pot vegetarian meals

• Curried Butternut Squash Soup (One Pot)
• Zucchini Noodles With Pesto (One Pot)
• Instant Pot Potato Soup
• Roasted Cauliflower Steak (One Pan)
• Instant Pot Pumpkin Soup

Recipe