Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: American
Ingredients: 3 pounds red potatoes, cut into 1-inch pieces; 4 tablespoons butter, room temperature; 1 cup sour cream; ½–1 teaspoon kosher salt; ½ teaspoon freshly ground black pepper; ½ teaspoon granulated garlic (or garlic powder); ½ teaspoon paprika; 1 medium broccoli crown (about 2–3 cups florets); 3 cups cooked, chopped chicken; 2 cups shredded cheese (Monterey Jack, Cheddar, or Mexican blend), divided

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A creamy, comforting casserole layering fluffy mashed potatoes, tender chicken, and broccoli, topped with melty cheese for an irresistible family‑style bake. This dish brings together everything I love about cozy, satisfying meals into one warm and hearty pan. Chicken Broccoli Mashed Potato Casserole

Why You’ll Love This Recipe

I make this casserole when I want something rich, easy, and full of flavor. The mashed potatoes are buttery and smooth, the chicken adds protein, and the broccoli gives a pop of freshness. Topped with gooey cheese, it’s the kind of meal that makes everyone happy at the table. I love that I can use leftovers or whatever cheese I have on hand, making it flexible and budget-friendly.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

3 pounds red potatoes, cut into 1‑inch pieces
4 tablespoons butter, room temperature
1 cup sour cream
½–1 teaspoon kosher salt
½ teaspoon freshly ground black pepper
½ teaspoon granulated garlic (or garlic powder)
½ teaspoon paprika
1 medium broccoli crown (about 2–3 cups florets)
3 cups cooked, chopped chicken
2 cups shredded cheese (Monterey Jack, Cheddar, or Mexican blend), divided

Directions

I preheat the oven to 350 °F (175 °C) and grease a 10‑inch square baking dish with butter or nonstick spray.
I place the potatoes in a large pot, cover with water, bring to a boil, and cook until fork‑tender, about 10–15 minutes. Then I drain and return them to the warm pot.
While the potatoes cook, I steam or roast the broccoli just until slightly crisp. I drain it well.
On the turned‑off burner or low heat, I mash the potatoes and stir in the butter, sour cream, salt, pepper, garlic, and paprika until smooth and creamy.
I add the broccoli, chicken, and 1 cup of the shredded cheese to the mashed potatoes. I mix it all together and transfer the mixture to the prepared baking dish.
I sprinkle the remaining 1 cup of cheese over the top.
I bake the casserole for 20–25 minutes, or until the cheese is melted and everything is hot and bubbly. Then I serve it warm.

Servings and timing

This casserole makes about 8 hearty servings.

Prep Time: 15 minutes
Cook Time: 10–15 minutes (boiling potatoes) + 20–25 minutes (baking)
Total Time: Around 45 minutes

Variations

I like to switch things up depending on what I have in the kitchen. Sometimes I use sweet potatoes for a unique twist, or I swap broccoli for cauliflower or peas. When I want even more richness, I stir in a few tablespoons of cream cheese with the mashed potatoes. If I need a vegetarian version, I leave out the chicken and add sautéed mushrooms or roasted veggies. For a little spice, I mix in a dash of cayenne or some chopped green chiles.

Storage/Reheating

I store leftovers in an airtight container in the fridge for up to 4 days. When reheating, I cover and warm individual portions in the microwave or reheat the whole dish in a 350 °F oven until hot—usually about 15–20 minutes. This casserole also freezes well for up to 2 months. I wrap it tightly to prevent freezer burn and thaw overnight in the fridge before reheating.

FAQs

Can I make this casserole ahead of time?

Yes, I prepare the casserole up to the point of baking, then cover and refrigerate it for up to 24 hours. When I’m ready to serve, I bake it as directed, adding a few extra minutes if it’s cold.

Is frozen broccoli okay to use?

Frozen broccoli works fine. I make sure to thaw and drain it completely so the casserole doesn’t get watery.

What type of chicken should I use?

Any cooked chicken works—rotisserie, grilled, or baked. I usually use what I have on hand, and it always turns out great.

Can I make this dairy-free?

Yes, I can use dairy-free butter, sour cream, and cheese alternatives. The texture and flavor will be slightly different, but still delicious.

How do I get the mashed potatoes extra smooth?

To get them really smooth, I mash them while still hot and add warm butter and sour cream. I also make sure not to overwork them, which can make them gummy.

Conclusion

This chicken broccoli mashed potato casserole is one of my favorite comforting meals. It’s easy to make, satisfying, and great for feeding a crowd or prepping ahead. Whether I keep it classic or switch up the ingredients, it always comes out warm, flavorful, and just the kind of cozy dish I crave.