Cheesy Zucchini Casserole
A creamy, cheesy zucchini casserole loaded with tender zucchini, a rich cheese sauce, and a crispy golden topping. This comforting side dish is perfect for family dinners, potlucks, or holiday gatherings.
Prep Time: 20 minutes
Cook Time: 40 minutes
Total Time: 1 hour
Servings: 6
Ingredients
For the Casserole
4 medium zucchini, sliced into ¼-inch rounds
1 tablespoon olive oil
1 small onion, finely diced
3 cloves garlic, minced
2 tablespoons unsalted butter
2 tablespoons all-purpose flour
1 cup whole milk
½ cup heavy cream
1½ cups shredded sharp cheddar cheese
½ cup shredded mozzarella cheese
¼ cup grated Parmesan cheese
1 teaspoon Italian seasoning
½ teaspoon paprika
½ teaspoon salt
½ teaspoon black pepper
Crispy Topping
¾ cup panko breadcrumbs
2 tablespoons grated Parmesan cheese
1 tablespoon melted butter
1 teaspoon dried parsley
For a Gluten-Free Version:
Use gluten-free flour and gluten-free breadcrumbs.
Instructions
Step 1: Prepare the Zucchini
Preheat the oven to 375°F (190°C).
Lightly grease a 9×13-inch baking dish.
Sprinkle the zucchini slices with a little salt and let them rest for 15 minutes to release excess moisture.
Pat dry thoroughly with paper towels.
Step 2: Cook the Vegetables
Heat olive oil in a large skillet over medium heat.
Add the onion and cook for 4–5 minutes until softened.
Stir in the garlic and cook for 30 seconds.
Add the zucchini and cook for 4–5 minutes, just until slightly tender.
Remove from the heat.
Step 3: Make the Cheese Sauce
Melt the butter in a saucepan over medium heat.
Whisk in the flour and cook for 1 minute.
Gradually whisk in the milk and heavy cream until smooth.
Cook for 3–4 minutes, stirring constantly, until slightly thickened.
Stir in:
Cheddar cheese
Mozzarella cheese
Parmesan cheese
Italian seasoning
Paprika
Salt
Black pepper
Stir until the cheese has completely melted.
Step 4: Assemble the Casserole
Spread the zucchini mixture evenly in the prepared baking dish.
Pour the cheese sauce over the zucchini.
Stir gently to coat.
Step 5: Make the Topping
In a small bowl, combine:
Panko breadcrumbs
Parmesan cheese
Melted butter
Dried parsley
Sprinkle evenly over the casserole.
Step 6: Bake
Bake uncovered for 30–35 minutes, until bubbly and golden brown.
If needed, broil for 2–3 minutes for an extra crispy topping, watching carefully to prevent burning.
Step 7: Serve
Allow the casserole to rest for 5–10 minutes before serving.
Garnish with:
Fresh parsley
Extra Parmesan cheese
Freshly ground black pepper
Serving Suggestions
Grilled chicken
Baked salmon
Roast beef
Meatloaf
Pork chops
Garlic bread
Fresh green salad
Nutrition (Per Serving)
Calories: 320
Protein: 14 g
Carbohydrates: 14 g
Fat: 24 g
Saturated Fat: 13 g
Fiber: 2 g
Sugar: 6 g
Cholesterol: 65 mg
Sodium: 520 mg
Calcium: 340 mg
Iron: 1.2 mg
Nutrition values are approximate and may vary depending on the ingredients used.
Nut Information
Contains
Milk (Dairy): Cheddar cheese, mozzarella cheese, Parmesan cheese, milk, heavy cream, butter
Wheat/Gluten: All-purpose flour and panko breadcrumbs
Does Not Contain
Peanuts
Tree nuts
Eggs
Soy (unless present in packaged cheese or breadcrumbs)
Fish
Shellfish
Sesame (unless included in the breadcrumbs)
Nut Allergy Tips
This recipe contains no peanuts or tree nuts.
If serving someone with a severe nut allergy, choose dairy products and breadcrumbs that are certified nut-free or produced in a nut-free facility to avoid cross-contamination.
Frequently Asked Questions (Q&A)
1. Can I make this casserole ahead of time?
Yes. Assemble the casserole, cover it tightly, and refrigerate for up to 24 hours before baking.
2. Can I freeze it?
Yes. Bake and cool completely, then wrap well and freeze for up to 2 months. Thaw overnight in the refrigerator before reheating.
3. How do I keep the casserole from becoming watery?
Salt the zucchini, let it rest for 15 minutes, and pat it dry thoroughly before cooking to remove excess moisture.
4. Can I use yellow squash instead of zucchini?
Absolutely. Yellow squash works just as well or use a combination of both for added color.
5. Can I add protein?
Yes. Add cooked shredded chicken, diced ham, crumbled bacon, or cooked ground turkey to make it a complete meal.
6. What other cheeses work well?
Gruyère, Monterey Jack, Colby Jack, Fontina, Gouda, or Pepper Jack are excellent substitutes or additions.
7. Can I make it low carb?
Yes. Omit the breadcrumb topping or replace it with crushed pork rinds or extra Parmesan cheese for a keto-friendly version.
8. How do I store leftovers?
Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat in the oven at 350°F (175°C) for 15–20 minutes or microwave until heated through.
9. Can I use frozen zucchini?
Fresh zucchini is recommended for the best texture. If using frozen zucchini, thaw completely and squeeze out as much liquid as possible before cooking.
10. What can I serve with this casserole?
It pairs wonderfully with grilled steak, roasted chicken, baked fish, pork tenderloin, pasta dishes, or a crisp garden salad for a complete and satisfying meal.
