Chicken Zucchini Casserole Recipe

Chicken Zucchini Casserole Recipe tastes creamy, cheesy, and cozy with tender chicken and soft zucchini tucked under a golden topping. It works perfectly for busy weeknights, small family dinners, or meal prep, and you can get it on the table in about 50 minutes. I tested this version on my own picky crew, and they scraped the pan so clean I almost skipped washing it.

Why You Should Try This Chicken Zucchini Casserole Recipe

This Chicken Zucchini Casserole Recipe packs protein, veggies, and comfort into one pan, so you skip juggling three different pots. The zucchini stays tender, the chicken stays juicy, and the sauce turns rich and cheesy without feeling heavy.

You can use leftover chicken, rotisserie chicken, or even canned chicken in a pinch, which saves time and dishes. The recipe also works well with gluten free swaps and low carb tweaks, so you can fit it into different eating styles without losing flavor.

“This Chicken Zucchini Casserole Recipe tastes like cozy chicken pot pie met cheesy veggie bake and decided to become a weeknight regular. ★★★★★”

Ingredients You’ll Need

Chicken & Veggies

• 3 cups cooked chicken, shredded or diced
  • Rotisserie chicken adds great flavor and saves time.
  • Use leftover grilled or baked chicken if you have it.
• 3 medium zucchini, sliced into half moons
  • Keep the skin on for color and texture.
• 1 small yellow onion, finely chopped
• 2 cloves garlic, minced
• 1 cup carrots, thinly sliced or diced
• 1 cup frozen peas or frozen mixed vegetables
  • Do not thaw; they cook perfectly in the oven.

Sauce & Seasoning

• 2 tablespoons olive oil or butter
• 2 tablespoons all purpose flour
  • Use a 1:1 gluten free flour blend if needed.
• 1 ½ cups chicken broth
  • Use low sodium broth so you control the salt.
• ½ cup milk or half and half
  • Whole milk gives a creamier texture.
• 1 teaspoon kosher salt, plus more to taste
• ½ teaspoon black pepper
• 1 teaspoon dried Italian seasoning
• ½ teaspoon garlic powder
• ½ teaspoon onion powder
• ¼ teaspoon smoked paprika or regular paprika

Cheese & Topping

• 1 ½ cups shredded mozzarella cheese
  • Pre shredded works, but block cheese melts smoother.
• ½ cup shredded sharp cheddar cheese
• 1 cup seasoned bread crumbs or crushed butter crackers
  • Use panko for extra crunch or gluten free crumbs if needed.
• 2 tablespoons grated Parmesan cheese
• 2 tablespoons melted butter or olive oil

Optional Add Ins

• ½ cup cooked rice or quinoa for extra bulk
• ½ cup sliced mushrooms
• ¼ cup chopped fresh parsley or chives for garnish

Equipment

• 9×13 inch baking dish
• Large skillet or sauté pan
• Medium saucepan (for sauce)
• Mixing bowls
• Whisk
• Cutting board and sharp knife

Tips & Tricks

• Salt the zucchini lightly and pat it dry to avoid a watery casserole.
• Use hot cooked chicken or warm it slightly so the casserole heats evenly.
• Shred cheese from a block to get a smoother, meltier top.
• Taste the sauce before you pour it over and adjust salt and pepper right away.
• Keep the veggies in small, even pieces so they cook at the same rate.
• Cover loosely with foil if the topping browns too quickly.
• Let the casserole rest 8 to 10 minutes before serving so it sets and slices cleanly.

How to Make Chicken Zucchini Casserole Recipe

Prep the Oven and Pan

1. Heat your oven to 375°F.
2. Grease a 9×13 inch baking dish with a little butter or oil.
3. Set the dish aside while you prep the filling and topping.

Prep the Zucchini and Veggies

1. Slice the zucchini into half moons about ¼ inch thick.

2. Sprinkle the slices with a pinch of salt and set them on a clean towel for 10 minutes.

3. Pat the zucchini dry to remove extra moisture.

4. Chop the onion, carrots, and any optional veggies like mushrooms.

5. Mince the garlic.

Cook the Veggies and Chicken Mixture

1. Heat 2 tablespoons olive oil or butter in a large skillet over medium heat.

2. Add onion and carrots and cook 4 to 5 minutes until they soften and start to turn golden.

3. Stir in garlic and cook 30 seconds so it smells fragrant.

4. Add the zucchini and cook 3 to 4 minutes until it starts to soften but still holds shape.

5. Stir in frozen peas or mixed vegetables and cook 1 to 2 minutes.

6. Fold in the cooked chicken and turn off the heat.

7. Sprinkle in Italian seasoning, garlic powder, onion powder, paprika, salt, and pepper.

8. Toss everything so the chicken and veggies carry the seasoning evenly.

9. Transfer this mixture to the greased baking dish and spread it into an even layer.

Make the Creamy Sauce

1. In a medium saucepan, melt 2 tablespoons butter or heat 2 tablespoons olive oil over medium heat.

2. Whisk in the flour and cook 1 to 2 minutes until it looks smooth and slightly golden.

3. Slowly pour in the chicken broth while you whisk so no lumps form.

4. Add the milk and keep whisking until the sauce thickens, about 3 to 5 minutes.

5. Turn the heat to low and stir in half of the mozzarella and half of the cheddar.

6. Season the sauce with a pinch of salt and pepper and taste it.

7. Once the cheese melts and the sauce turns silky, pour it evenly over the chicken and veggie mixture in the baking dish.

8. Gently nudge the sauce with a spatula so it seeps down into the corners.

Add Cheese and Crunchy Topping

1. Sprinkle the remaining mozzarella and cheddar over the sauced casserole.

2. In a small bowl, mix bread crumbs, Parmesan, and melted butter or olive oil.

3. Stir until the crumbs look evenly coated and slightly clumpy.

4. Scatter the crumb mixture evenly over the cheese layer.

5. Place the baking dish on the center rack of the oven.

Bake the Casserole

1. Bake at 375°F for 25 to 30 minutes until the top looks golden and the edges bubble.

2. If the top browns too fast, tent the dish loosely with foil and finish baking.

3. Check that the center feels hot and the cheese looks fully melted.

4. Remove the casserole from the oven and let it rest 8 to 10 minutes.

5. Sprinkle chopped parsley or chives on top if you like a fresh pop of color.

6. Slice into squares and serve warm.

What to Serve with Chicken Zucchini Casserole Recipe

This Chicken Zucchini Casserole Recipe pairs nicely with a simple green salad or a crisp cucumber tomato salad. You can spoon it over plain rice, quinoa, or mashed potatoes if you want a heartier plate. Garlic bread, warm dinner rolls, or toasted baguette slices help scoop up every bit of the creamy sauce. A side of steamed green beans or roasted broccoli rounds out the meal without much extra work.

Storage Options

• Store leftovers in an airtight container in the fridge for up to 4 days.
• Reheat single portions in the microwave in 45 to 60 second bursts until hot, or warm a covered baking dish in a 325°F oven for 15 to 20 minutes.
• Freeze cooled portions in freezer safe containers for up to 2 months, and label with the date.
• Thaw overnight in the fridge, then reheat in the oven so the topping turns crisp again.