There’s something about the creamy, cheesy warmth of a homemade casserole that brings instant comfort—and this Summer Squash Casserole hits all the right notes.
Every spoonful is packed with tender squash, savory veggies, a subtle kick from green chiles, and melty cheese that wraps it all together.
Why I Love This Recipe
Creamy, cheesy texture with the perfect balance of veggies
Naturally sweet squash and corn paired with savory mushrooms
Melts beautifully with Monterey Jack or Cheddar
Great for potlucks, family dinners, or as a holiday side
Simple ingredients turned into cozy, comforting magic
What You’ll Need (Ingredient Highlights)
Summer squash – Fresh, chopped squash is the base of this dish. Microwave-steamed to save time.
Bell peppers & onion – Adds color and a nice aromatic sweetness.
Mushrooms – For earthiness and extra umami.
Green chiles – Optional, but highly recommended for a gentle kick.
Stuffing mix or cornbread – Soaks up flavor and adds texture.
Cheddar or Monterrey Jack cheese – Melts beautifully and brings everything together.
Pro Tips Before You Start
Make sure to drain the cooked squash well to avoid a watery casserole.
If using leftover cornbread instead of stuffing mix, crumble it first.
Taste before adding salt—stuffing mixes often already contain seasoning.
For extra crisp edges, bake in a shallow ceramic dish and broil for 1–2 minutes at the end.
How to Make Summer Squash Casserole
Step 1: Cook the Squash
Place chopped squash with a tablespoon of water in a microwave-safe bowl.
Cover and microwave on HIGH for 8–9 minutes until tender.
Mash lightly and drain thoroughly, then set aside.
Step 2: Sauté the Vegetables
In a large skillet, melt butter over medium heat.
Add chopped onion and bell peppers, sauté until softened.
Add mushrooms and cumin, and cook for another 2–3 minutes.
Step 3: Make the Sauce
Sprinkle in flour and cook, stirring constantly for 2 minutes.
Gradually pour in milk while whisking, and cook over medium-low until thickened to a gravy-like consistency.
Step 4: Mix Everything Together
Add corn, green chiles, and the cooked squash.
Season with salt and pepper, then fold in stuffing (or cornbread) and shredded cheese.
Step 5: Bake the Casserole
Transfer mixture to a greased 1½-quart casserole dish.
Bake at 400°F (200°C) for 20 minutes.
Sprinkle extra cheese on top during the last 5 minutes for a bubbly finish.
What to Serve It With
This Summer Squash Casserole pairs perfectly with:
Grilled chicken or pork chops
A crisp green salad
Cornbread muffins
Roasted potatoes or herbed rice
Variations / Substitutions
Add protein: Fold in cooked shredded chicken or browned ground turkey.
Swap veggies: Use zucchini, yellow squash, or a mix of both.
Cheese options: Try Gruyère, Fontina, or Pepper Jack for more flair.
No microwave? Steam squash on the stovetop instead.
Storage & Leftovers
Fridge: Store in an airtight container for up to 4 days.
Freezer: Freeze in individual portions for up to 2 months.
Reheat: Microwave or bake until warmed through—add fresh cheese on top if desired.
FAQs
Can I use canned squash instead of fresh?
Fresh is preferred, but drained canned squash can work in a pinch—just expect a softer texture.
What’s the best stuffing mix to use?
Any dry boxed stuffing will work. Cornbread stuffing is especially delicious.
Can I make it ahead of time?
Yes! Assemble and refrigerate (unbaked) for up to 24 hours. Bake just before serving.
Is it vegetarian?
Yes, this recipe is fully vegetarian as written.
How do I keep the casserole from getting watery?
Be sure to drain the cooked squash very well and avoid overcooking the veggies.
Can I use almond milk or dairy-free cheese?
Absolutely! Use your preferred milk and cheese alternatives, but results may vary slightly.
What can I use instead of green chiles?
Try diced jalapeños or skip them altogether if you prefer mild flavor.
Final Thoughts
This Summer Squash Casserole is the perfect celebration of seasonal produce.
Whether it’s your main event or a satisfying side dish, it brings comfort, warmth, and just the right amount of cheesy goodness.
I’ve made this countless times and it’s always a crowd-pleaser—give it a try and you’ll see why.

Cheesy Summer Squash Casserole
Ingredients
- 4 cups 784 g summer squash, chopped (3 small or 2 medium)
- 2 tablespoons 28 g butter
- ½ medium 75 g onion, chopped
- ½ cup 75 g red or green bell peppers, chopped
- 8 ounces 227 g white mushrooms, sliced
- ¼ teaspoon cumin
- 1 tablespoon all-purpose flour
- 1 cup 114 g milk
- 1 cup 82 g frozen corn
- 4 ounces 114 g green chiles, chopped (adjust to taste)
- 1 cup 102 g stuffing mix or crumbled cornbread
- ½ teaspoon salt
- Freshly ground black pepper to taste
- 1 cup 113 g shredded Cheddar or Monterrey Jack cheese
Instructions
- Cook chopped squash with water in microwave on HIGH for 8–9 minutes. Mash and drain well.
- In a large skillet, melt butter. Sauté onion and bell pepper until soft.
- Add mushrooms and cumin; cook 2–3 minutes more.
- Stir in flour and cook for 2 minutes. Gradually add milk and stir until sauce thickens.
- Combine corn, green chiles, squash, stuffing mix, and cheese. Season with salt and pepper.
- See full steps with tips & photos → https://mischacrossing.com/easy-cheesy-summer-squash-casserole-recipe/