Best Spinach Chicken Casserole

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Growing up, I thought casseroles were just those mushy, cream-of-something dishes that showed up at every potluck. My mom would mix whatever leftovers we had with a can of soup and call it dinner. I avoided them completely in my early cooking days.

But then I discovered that casseroles don’t have to be that way at all. This spinach chicken casserole changed my mind completely – it’s nothing like those potluck disasters. It’s just good ingredients, layered together, that come out of the oven tasting like something you’d actually want to eat.

What Kind of Chicken Should I Use?

For this casserole, boneless, skinless chicken breasts are your best bet, though you could also use chicken tenderloins if that’s what you have on hand. Regular chicken breasts from the grocery store work perfectly fine, but if you can find air-chilled chicken, it often has better texture and flavor since it hasn’t absorbed extra water during processing. When preparing the chicken, try to slice your breasts into even-thickness pieces – this helps them cook at the same rate and keeps them juicy. If your chicken breasts are particularly thick, you might want to butterfly them or pound them slightly to ensure they cook evenly in the casserole.

Options for Substitutions

This casserole recipe is pretty adaptable and here are some easy swaps you can try:

• Chicken breast: You can easily swap chicken breasts with boneless chicken thighs, or even use leftover rotisserie chicken. If using pre-cooked chicken, just skip the initial cooking step.
• Fresh spinach: No fresh spinach? Use frozen spinach instead – just make sure to thaw and squeeze out all the excess water. You’ll need about 10 ounces of frozen spinach to equal 1 pound fresh.
• Monterey Jack cheese: Feel free to use mozzarella, white cheddar, or a Mexican cheese blend instead. Any good melting cheese will work well here.
• Mayo and sour cream: You can use all mayo or all sour cream if you’re missing one. Greek yogurt is also a good substitute for sour cream if you’re looking for a lighter option.
• Parmesan cheese: Romano or Asiago cheese can work in place of parmesan. Just make sure to use freshly grated cheese rather than the pre-grated kind for the best melting.
• Garlic salt: Out of garlic salt? Use 1/4 teaspoon regular salt plus 1/4 teaspoon garlic powder instead.

Watch Out for These Mistakes While Cooking

The biggest challenge when making spinach chicken casserole is ending up with dry, overcooked chicken – to prevent this, make sure to slice your chicken breasts evenly and remove them from the oven when they reach 155°F internally, as they’ll continue cooking in the hot casserole.

Raw, watery spinach can ruin your casserole’s texture, so take time to properly wilt and drain your fresh spinach before adding it to the dish – simply sauté it for 2-3 minutes and press out any excess moisture with paper towels.

When it comes to the creamy sauce, avoid rushing the mixing process – thoroughly combine the mayo, sour cream, and cheeses at room temperature for a smooth, clump-free mixture that will coat everything evenly.

For the best cheese pull and golden-brown top, switch your oven to broil for the final 2-3 minutes, but keep a close eye on it as the cheese can go from perfectly melted to burnt in seconds.

What to Serve With Spinach Chicken Casserole?

This creamy, cheesy casserole pairs really well with simple sides that can balance out its richness. A scoop of fluffy white rice or buttered egg noodles makes an excellent base to soak up all the delicious sauce. For a fresh contrast, try serving it with some roasted cherry tomatoes or a simple mixed green salad dressed with light vinaigrette. If you’re looking to add more veggies to the meal, some steamed broccoli or roasted carrots would work great on the side – they’re simple enough not to compete with the casserole’s flavors but still add nice color and nutrition to your plate.

Storage Instructions

Keep Fresh: This spinach chicken casserole stays good in the fridge for up to 4 days when stored in an airtight container. It’s one of those dishes that’s perfect for meal prep since you can portion it out for quick lunches or dinners throughout the week.

Freeze: Want to save some for later? Let the casserole cool completely, then cover it tightly with foil or transfer portions to freezer-safe containers. It’ll keep well in the freezer for up to 3 months. Just remember that cream-based dishes might separate a bit when frozen.

Reheat: To warm up your casserole, pop it in the oven at 350°F for about 20-25 minutes if thawed, or 40-45 minutes if frozen. You can also microwave individual portions for 2-3 minutes, stirring halfway through. Cover with a paper towel to prevent any splatters.

Preparation Time	10-15 minutes
Cooking Time	20-25 minutes
Total Time	30-40 minutes
Level of Difficulty	Medium

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1800-2000
• Protein: 120-135 g
• Fat: 130-145 g
• Carbohydrates: 10-15 g

Ingredients

• 1 pound chicken breast halves (two pieces, sliced in halves)
• 8 ounces fresh spinach
• 8 ounces shredded monterey jack cheese
• 1/2 cup mayo
• 1/2 cup sour cream
• 1/2 cup grated parmesan cheese
• 1/2 teaspoon black pepper
• 1 teaspoon garlic salt

Step 1: Preheat and Prepare the Baking Dish

Begin by preheating your oven to 500°F.

While the oven is heating, lightly spray a 13 x 9-inch baking dish with cooking spray to prevent sticking.

Set the prepared dish aside as you move on to the next steps.

Step 2: Prepare the Creamy Sauce

While your oven is preheating, take a moment to combine the ingredients for your creamy sauce in a mixing bowl.

Ensure the mixture is smooth and well-blended, making it easy to spread over the casserole.

Step 3: Assemble the Casserole

First, pack the bottom of your prepared casserole dish with a layer of spinach.

Make sure the spinach is spread evenly across the dish.

Next, place uncooked chicken breasts on top of the spinach layer.

Pour the creamy sauce mixture over the chicken and spinach, spreading it evenly with a spatula to ensure full coverage.

Step 4: Add Cheese and Bake

Sprinkle shredded Monterey Jack cheese over the top of the casserole.

Once your oven is preheated, place the dish on the bottom rack and bake for 20-25 minutes.

Keep an eye on the dish, and remove it from the oven once the spinach has shrunk significantly and the chicken breasts are thoroughly cooked.

The cheese should be melted and slightly bubbly.

Step 5: Serve and Enjoy

After baking, carefully remove the dish from the oven and let it sit for a few minutes to allow the flavors to meld.

Serve the dish hot, enjoying the creamy combination of chicken, spinach, and cheese.

Bon appétit!