Preheat the Oven

• Preheat your oven to 350°F (175°C).

2. Sauté the Vegetables

• Melt butter in a medium-sized saucepan over medium-high heat.
• Add chopped onion and sauté until softened, about 3 minutes.
• Add broccoli florets and sauté for another 3–4 minutes until slightly tender.

3. Prepare the Casserole Mixture

• In a large mixing bowl, combine sautéed broccoli and onion, cooked rice, cream of chicken soup, sour cream, milk, shredded chicken, cheddar cheese, salt, pepper, and garlic powder.
• Mix thoroughly until well combined.

4. Assemble the Casserole

• Grease a 9×13-inch casserole dish.
• Spread the prepared mixture evenly into the dish.

5. Add the Topping

• In a small bowl, mix Panko breadcrumbs, grated Parmesan, and melted butter.
• Sprinkle the topping evenly over the casserole.

6. Bake the Casserole

• Place the dish in the preheated oven and bake for 20–25 minutes.
• The casserole is done when the topping is golden brown and the dish is heated through.

7. Serve and Enjoy

• Let the casserole cool for a few minutes before serving.
• Garnish with fresh parsley or additional cheese if desired.