Introduction

This Chicken Zucchini Casserole is a comforting and flavorful dish perfect for a wholesome weeknight dinner. Tender chicken pieces combine with sautéed vegetables and a creamy, cheesy sauce for a satisfying bake that the whole family will enjoy.

The image shows a close-up of a baked casserole in a white baking dish with a wooden spoon scooping a portion. The dish has chunks of golden brown chicken mixed with thick slices of green zucchini and brown mushrooms, all covered by a melted, bubbly layer of lightly browned cheese. Small sprigs of fresh green herbs are sprinkled on top, adding a touch of color. The casserole looks creamy and rich, with the cheese forming a slightly crispy, caramelized crust. The background is a white marbled surface with a gray cloth partially visible on the side. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

1 lb boneless skinless chicken breast, cut into 1-inch pieces
3/4 tsp sea salt, divided (1/2 tsp and 1/4 tsp)
1/2 tsp black pepper, divided
2 tbsp olive oil, divided
8 oz mushrooms, sliced
1/2 large onion, diced
3 medium zucchini, cut into half-moons
1/2 cup heavy cream
1/3 cup reduced sodium chicken broth
6 oz Swiss Gruyere shredded cheese blend, divided
1/2 cup sour cream

Instructions

Step 1: Place the chicken pieces in a large bowl and pat dry with paper towels. Season with 1/2 teaspoon of salt and 1/4 teaspoon of pepper.
Step 2: Heat 1 tablespoon of olive oil in a 12-inch skillet over medium-high heat. Add the chicken and sear for 5–6 minutes, turning every few minutes until browned and cooked through. Remove chicken to a large bowl, cover to keep warm, and set aside.
Step 3: Add the remaining 1 tablespoon olive oil to the skillet and reduce heat to medium. Add mushrooms and onions and cook for 7–10 minutes, until mushrooms are soft and no liquid remains in the pan.
Step 4: Increase heat to medium-high. Add zucchini and season with remaining 1/4 teaspoon salt and 1/4 teaspoon pepper. Sauté, stirring occasionally, for about 10 minutes uncovered until zucchini is soft and slightly browned. Drain any liquid and transfer vegetables to the bowl with the chicken.
Step 5: Preheat the oven to 400°F (191°C).
Step 6: Add heavy cream and chicken broth to the same skillet. Scrape the bottom to release browned bits. Bring to a boil over medium-high heat, then simmer for about 5 minutes until sauce thickens to coat the back of a spoon.
Step 7: Reduce heat to low and stir in 3 ounces of shredded cheese until melted. Remove from heat and stir in sour cream. Season with salt and pepper to taste if needed.
Step 8: Drain any additional liquid from the chicken and vegetables mixture. Pour the sauce over the chicken and veggies and stir to combine.
Step 9: Transfer the mixture to a 10×7-inch casserole dish. Sprinkle remaining 3 ounces of shredded cheese on top.
Step 10: Bake for about 10 minutes until cheese is melted. For a golden top, broil for 2–3 minutes if desired.

Tips & Variations

Use other cheese varieties like mozzarella or cheddar if Swiss Gruyere isn’t available.
Add garlic or fresh herbs like thyme or rosemary for extra flavor.
For a lower-fat option, substitute sour cream with Greek yogurt.
Ensure to pat the chicken dry well before cooking for a better sear.
If zucchini releases too much liquid, draining it thoroughly prevents a soggy casserole.

Storage

Store leftover casserole in an airtight container in the refrigerator for up to 3 days. Reheat in the oven at 350°F (175°C) until warmed through, or microwave in short intervals stirring occasionally. This dish is not recommended for freezing as the texture of the zucchini and sauce may change.

How to Serve

A white rectangular baking dish filled with a rich vegetable casserole, showing several layers of golden melted cheese with browned spots on top, mixed with slices of green zucchini and soft brown mushrooms visible underneath. The cheese layer is bubbly and slightly crispy at the edges, sprinkled with small bright green parsley flakes for garnish. The vegetables beneath look tender and slightly cooked through, blending with a creamy sauce. The dish rests on a white marbled surface with fresh green zucchini and chopped herbs nearby, adding freshness to the scene. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use frozen chicken for this casserole?

Fresh or thawed chicken works best for even cooking. If using frozen, ensure it is fully thawed and patted dry before seasoning and cooking to prevent excess moisture.

Can I make this casserole ahead of time?

Yes, you can prepare the chicken and vegetables in advance and combine everything just before baking. This saves time on the day you want to serve it.