Creamy Chicken and Spinach Casserole is a comforting dish that brings together tender pieces of chicken, fresh spinach, and a rich, creamy sauce baked to bubbly perfection. It has a lovely mix of textures—the softness of the cooked spinach and chicken blends beautifully with the creamy sauce, making every bite feel warm and satisfying.
I love making this casserole on busy weeknights because it’s so simple yet feels like a special meal. One of my favorite parts is how the spinach sneaks in a little green goodness without overpowering the dish. I usually sprinkle some cheese on top before baking because it melts into a golden, delicious crust that everyone always asks for seconds of.
This casserole is perfect for sharing with family or friends, especially when you want something cozy but not too complicated. I like serving it alongside a fresh salad or crusty bread to soak up all that creamy sauce. It’s the kind of meal that reminds me of home-cooked dinners and the comfort that simple food can bring to the table.
Key Ingredients & Substitutions
Chicken breasts: These give the dish its hearty protein. You can use thighs for a juicier option or pre-cooked chicken to save time.
Spinach: Fresh spinach is best for flavor and texture, but frozen works well too. Just make sure to drain it well to avoid watery sauce.
Heavy cream and milk: They create the rich, creamy sauce. For a lighter version, swap heavy cream for half-and-half or use a dairy-free milk and cream alternative.
Cheese: Mozzarella adds stretchiness, while Parmesan brings a salty depth. If needed, use cheddar or Gruyère as tasty substitutes.
Flour (optional): Helps thicken the sauce. You can replace it with cornstarch mixed with cold water for a gluten-free option.
How Do I Make the Sauce Thick and Creamy Without Lumps?
Thickening the sauce evenly is key for a delicious casserole. Here’s how I do it:
- After sautéing the onion, add garlic, spinach, then pour in the liquids gradually while stirring.
- If using flour, sprinkle it over the veggies and stir well to coat before adding liquids. This creates a smooth base, preventing lumps.
- Whisk constantly while the sauce heats, letting it thicken gently over medium heat.
- Keep an eye on the sauce—once it’s thick enough to coat the back of a spoon, it’s ready.
A slow and steady approach makes the sauce creamy and lump-free every time.
Equipment You’ll Need
- Large oven-safe skillet – great for cooking chicken and baking the casserole in one dish, saving time and cleanup.
- Wooden spoon or silicone spatula – perfect for stirring the creamy sauce without scratching your pan.
- Measuring cups and spoons – to get your liquid and seasoning amounts just right.
- Sharp knife and cutting board – for chopping onions, garlic, and chicken safely.
- Oven mitts – important for handling the hot skillet coming out of the oven.
Flavor Variations & Add-Ins
- Swap chicken breasts for cooked shredded rotisserie chicken for an even quicker meal with great flavor.
- Add sautéed mushrooms or sun-dried tomatoes to deepen the flavor and add texture to the creamy sauce.
- Stir in a pinch of red pepper flakes or smoked paprika for a hint of warmth and smoky depth.
- Use different cheese blends like cheddar or Monterey Jack for a twist on the classic creamy and cheesy taste.
Creamy Chicken and Spinach Casserole
Ingredients You’ll Need:
- 2 tablespoons olive oil or butter
- 4 boneless, skinless chicken breasts (about 1.5 lbs)
- Salt and pepper, to taste
- 4 cloves garlic, minced
- 1 small onion, finely chopped
- 10 oz fresh spinach (or frozen, thawed and drained)
- 1 cup heavy cream
- 1/2 cup whole milk
- 1/2 cup chicken broth
- 1 teaspoon dried Italian seasoning or mixed herbs
- 1/4 teaspoon ground nutmeg (optional)
- 1 cup shredded mozzarella cheese, divided
- 1/2 cup grated Parmesan cheese, divided
- 1 tablespoon all-purpose flour (optional, for thickening)
- Fresh parsley or dried parsley flakes, for garnish (optional)
How Much Time Will You Need?
This casserole takes about 15 minutes to prepare and cook on the stove, plus 15-20 minutes baking in the oven. You’ll also want to rest the dish for 5 minutes to let everything settle and get extra creamy before serving, so all together plan for about 35 to 40 minutes.
Step-by-Step Instructions:
1. Prepare the Chicken:
Preheat your oven to 375°F (190°C). Season the chicken breasts with salt and pepper on both sides. Heat olive oil or butter in a large oven-safe skillet over medium-high heat. Cook each chicken breast for about 5 minutes per side until golden brown but not fully cooked through. Remove from skillet and set aside.
2. Make the Creamy Spinach Sauce:
Reduce the heat to medium. Add the chopped onion to the skillet and sauté until translucent, about 3-4 minutes. Add the minced garlic and cook for another minute until fragrant. Stir in the spinach and cook until wilted (or heat through if frozen). Slowly add the heavy cream, milk, and chicken broth. If you want a thicker sauce, sprinkle in the flour while stirring well to prevent lumps. Add Italian seasoning, nutmeg (if using), half the mozzarella, and half the Parmesan. Stir continuously until the sauce thickens, about 4-5 minutes.
3. Bake Your Casserole:
Return the chicken breasts to the skillet, nestling them into the creamy spinach sauce. Sprinkle the remaining mozzarella and Parmesan cheese evenly on top. Transfer the skillet to the preheated oven and bake uncovered for 15-20 minutes, or until the chicken is fully cooked (internal temperature of 165°F or 75°C) and the cheese is golden and bubbly. Let the casserole rest for 5 minutes before serving. Optionally, garnish with parsley for a fresh touch.
Serve hot, on its own or with crusty bread or a simple salad for a comforting and delicious meal.
Can I Use Frozen Spinach Instead of Fresh?
Yes, frozen spinach works well! Just make sure to thaw it completely and squeeze out excess moisture before adding it to the sauce to avoid a watery casserole.
Can I Make This Casserole Ahead of Time?
Absolutely! Prepare the casserole up to the baking step, then cover and refrigerate for up to 24 hours. When ready, bake as directed, adding a few extra minutes if needed to ensure it’s heated through.
How Should I Store Leftovers?
Store leftovers in an airtight container in the fridge for up to 3 days. Reheat gently in the oven or microwave, adding a splash of cream or milk if the sauce has thickened too much.
Can I Substitute the Chicken with Another Protein?
Yes! You can use cooked shredded chicken, turkey, or even firm tofu for a vegetarian twist. Adjust cooking times accordingly, especially if using pre-cooked ingredients.
