Loaded with cheese and lots of tender zucchini, this cheesy zucchini rice casserole is the perfect use for extra zucchini and the easiest comfort food to make with leftover rice!
I know hot and cheesy casseroles aren’t typically a summer food, but I’m thinking we can make an exception for this zucchini-loaded cheese bomb of a rice casserole.
It’s packed with so many summer veggies and the cheesy rice part of it isn’t something to sleep on.
One of those things you might want to consider diving facefirst into, in fact.
Best part? It’s like 50% veggies and 50% indulgent cheesy rice. It all balances out!
The fact that it uses up all a bunch of garden veggies that are at their peak right now (looking at you, zucchini) also pretty much seals the deal.
This Zucchini Rice Casserole features…
- Tender zucchini and summer squash cubes
- A rich cheese sauce smothering rice
- Two kinds of cheese and lots of basil + cherry tomatoes on top
Making the Zucchini Rice Casserole
(scroll down to the bottom of post for the full recipe)
Ingredients You Will Need
- Summer squash
- Yellow onion
- Vegetable oil
- Cheddar cheese
- Monterey jack cheese
- Heavy whipping cream
- All-purpose flour
- Cherry tomatoes
Can I Make This Casserole with Leftover Rice?
Yes, absolutely! This casserole is a perfect use for leftover rice you have sitting in the refrigerator.
We’ve had success making this casserole with white rice, brown rice, and jasmine rice. It’s very versatile for using a rice that suits your preference!
Tips for Perfect Zucchini Rice Casserole
- Cut zucchini and summer squash into 1-in cubes – this larger size keeps the zucchini and summer squash perfectly tender and prevents it from becoming too soft while the casserole bakes.
- Sear vegetables – this adds a little flavor the vegetables and helps get a jumpstart on cooking.
- Make bechamel sauce – this is just a fancy name for cheese sauce. This sauce adds a wonderful cheesy creaminess to the rice casserole.
- Top casserole with more cheese – no explanation needed I don’t think??
- Allow casserole to sit after baking – let the casserole sit about 5-10 minutes after baking so it sets a bit.
- Top casserole with fresh basil – this adds one last little burst of flavor.
Make Ahead Instructions
This casserole can be assembled entirely, covered, and stored in the refrigerator up to 4 days before baking.
When ready to bake, remove cover and bake per recipe instructions (add an additional 5-10 minutes of bake time if baking straight from the fridge)
If you like to meal prep your dinners for the week, I highly recommend going this route!
Storing and Reheating Casserole
Once baked, this casserole may be stored in refrigerator up to 6 days.
Reheat individual servings in the microwave 1-2 minutes. You can also reheat the entire pan in the oven at 400F for 25-30 minutes.
The rich cheesy rice and tender zucchini is seriously a match made in comfort food heaven! We seriously can’t stop eating this rice – it’s our current go-to when we have ANY leftover rice on hand.
If you’ve got a bumper crop of zucchini just waiting to be put to good use, I think you’ve found your solution!
Save this recipe using the ‘save to recipe box’ button below. If you make it, please let us know! Leave a comment + star rating below, or take a photo and tag it on Instagram with #wholeandheavenlyoven.
More dishes starring zucchini to try next!
- Mediterranean Zucchini Noodle Salad
- Charred Zucchini Sweet Corn Mexican Salad
- Sweet Corn Zucchini Curry
Cheesy Zucchini Rice Casserole
- 1 tablespoon vegetable oil
- 1 medium yellow onion, finely diced
- 2 medium zucchinis, cut into 1-in cubes
- 1 medium summer squash, cut into 1-in cubes
- 3 medium cloves garlic, minced
- 1 teaspoon dried oregano
- 2 tablespoons unsalted butter
- 2 tablespoons all-purpose flour
- 1 cup 2% or skim milk
- 2 tablespoons heavy whipping cream
- 1 cup shredded mild cheddar cheese, divided
- Salt and pepper to taste
- 4 cups cooked white or brown rice
- 1 cup frozen corn (optional)
- 1 cup shredded monetary jack cheese
- 1 cup halved cherry tomatoes
- 2 tablespoons minced fresh basil
- Preheat oven to 400F. Lightly grease a 9×13 casserole dish and set aside.
- Heat a large skillet to medium-high heat. Add oil and swirl to coat bottom. Add onion, zucchini, and summer squash and saute several minutes until vegetables are crisp-tender. Add garlic and oregano and cook 1 additional minute until fragrant. Remove from heat and set aside.
- In a small saucepan over medium heat, melt butter. Whisk flour into butter and cook 1-2 minutes until a light golden brown. Slowly whisk in milk and cream until sauce is smooth. Cook sauce over medium heat until bubbly and slightly thickened. Remove sauce from heat and add 1/2 cup cheddar cheese.
- Add rice, sauce, and corn to vegetables in skillet and fold until evenly combined. Season rice with salt and pepper to taste if needed.
- Scrape rice mixture into prepared pan and top with remaining 1/2 cup cheddar and monterey jack cheese. Scatter halved tomatoes over top.
- Bake casserole at 400F 25-30 minutes until bubbly and lightly browned. Remove from oven and top with basil. Allow to stand several minutes before serving warm. Enjoy!