This casserole brings together juicy chicken, tender spinach, and a rich, cheesy cream sauce that feels like comfort food without the carb crash. It’s the kind of weeknight dinner you can pull together quickly and feel good about serving. The flavors are cozy and familiar, with a creamy texture that makes it taste indulgent.
Bonus: it reheats beautifully and works well for meal prep, so tomorrow’s lunch is already handled.
Keto Creamy Spinach Chicken Casserole - Comforting, Low-Carb, and Easy
Ingredients
- Chicken: 2 pounds boneless, skinless chicken breasts or thighs, cut into large chunks or left as whole fillets
- Spinach: 8 ounces fresh baby spinach (or 10 ounces frozen spinach, thawed and well-drained)
- Cream cheese: 8 ounces, softened
- Heavy cream: 1 cup
- Shredded cheese: 1 1/2 cups mozzarella or Monterey Jack, plus 1/2 cup grated Parmesan
- Butter or olive oil: 2 tablespoons
- Garlic: 3–4 cloves, minced
- Onion: 1/2 medium onion, finely chopped (optional but adds flavor)
- Chicken broth: 1/2 cup (low-sodium)
- Seasoning: 1 teaspoon kosher salt, 1/2 teaspoon black pepper, 1 teaspoon Italian seasoning or dried basil/oregano
- Smoked paprika: 1/2 teaspoon (optional, for a little warmth and color)
- Crushed red pepper flakes: A pinch, optional
- Lemon zest or juice: 1 teaspoon zest or 1 tablespoon juice, optional for brightness
- Fresh parsley: Chopped, for garnish
- Nonstick spray: For the baking dish
Instructions
- Prep the oven and dish: Preheat the oven to 375°F (190°C). Lightly grease a 9x13-inch casserole dish with nonstick spray or a little oil.
- Season the chicken: Pat the chicken dry. Season on both sides with salt, pepper, Italian seasoning, and smoked paprika if using.
- Sear the chicken: Heat a large skillet over medium-high heat with butter or olive oil. Sear the chicken 2–3 minutes per side until lightly golden. It doesn’t need to be cooked through. Transfer to a plate.
- Sauté aromatics: Lower heat to medium. Add onion and cook 3–4 minutes until soft. Stir in garlic and cook 30 seconds until fragrant.
- Build the cream sauce: Add chicken broth and heavy cream, stirring to combine. Whisk in cream cheese until smooth and melted. Stir in 1 cup mozzarella and 1/4 cup Parmesan. Season with a pinch of salt and pepper to taste. If using lemon zest or juice, add it now for brightness.
- Wilt the spinach: Add fresh spinach to the sauce in batches, stirring until wilted. If using frozen spinach, make sure it’s fully thawed and very well squeezed, then fold it in.
- Assemble the casserole: Spread the creamy spinach mixture in the prepared dish. Nestle the seared chicken pieces into the sauce. Spoon a little sauce over the top so the chicken is coated.
- Top with cheese: Sprinkle remaining mozzarella and Parmesan over the casserole. Add a pinch of red pepper flakes if you like a mild kick.
- Bake: Bake uncovered for 20–25 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the sauce is bubbling.
- Rest and garnish: Let the casserole rest 5–10 minutes to thicken slightly. Sprinkle with chopped parsley before serving.
What Makes This Recipe So Good
- Simple, satisfying flavors: Creamy garlic sauce, melty cheese, and well-seasoned chicken make this a crowd-pleaser, even for people who aren’t eating keto.
- Low-carb and high-protein: You’ll get a filling, balanced meal that keeps you on track with your goals.
- Quick prep: Everything goes into one casserole dish after a short stovetop sear, then the oven does the rest.
- Flexible ingredients: Swap in different cheeses or add low-carb veggies without changing the overall vibe.
- Great for leftovers: The sauce keeps the chicken moist, so it reheats without drying out.
What You’ll Need
- Chicken: 2 pounds boneless, skinless chicken breasts or thighs, cut into large chunks or left as whole fillets
- Spinach: 8 ounces fresh baby spinach (or 10 ounces frozen spinach, thawed and well-drained)
- Cream cheese: 8 ounces, softened
- Heavy cream: 1 cup
- Shredded cheese: 1 1/2 cups mozzarella or Monterey Jack, plus 1/2 cup grated Parmesan
- Butter or olive oil: 2 tablespoons
- Garlic: 3–4 cloves, minced
- Onion: 1/2 medium onion, finely chopped (optional but adds flavor)
- Chicken broth: 1/2 cup (low-sodium)
- Seasoning: 1 teaspoon kosher salt, 1/2 teaspoon black pepper, 1 teaspoon Italian seasoning or dried basil/oregano
- Smoked paprika: 1/2 teaspoon (optional, for a little warmth and color)
- Crushed red pepper flakes: A pinch, optional
- Lemon zest or juice: 1 teaspoon zest or 1 tablespoon juice, optional for brightness
- Fresh parsley: Chopped, for garnish
- Nonstick spray: For the baking dish
Step-by-Step Instructions
- Prep the oven and dish: Preheat the oven to 375°F (190°C). Lightly grease a 9×13-inch casserole dish with nonstick spray or a little oil.
- Season the chicken: Pat the chicken dry. Season on both sides with salt, pepper, Italian seasoning, and smoked paprika if using.
- Sear the chicken: Heat a large skillet over medium-high heat with butter or olive oil.
Sear the chicken 2–3 minutes per side until lightly golden. It doesn’t need to be cooked through. Transfer to a plate.
- Sauté aromatics: Lower heat to medium.
Add onion and cook 3–4 minutes until soft. Stir in garlic and cook 30 seconds until fragrant.
- Build the cream sauce: Add chicken broth and heavy cream, stirring to combine. Whisk in cream cheese until smooth and melted.
Stir in 1 cup mozzarella and 1/4 cup Parmesan. Season with a pinch of salt and pepper to taste. If using lemon zest or juice, add it now for brightness.
- Wilt the spinach: Add fresh spinach to the sauce in batches, stirring until wilted.
If using frozen spinach, make sure it’s fully thawed and very well squeezed, then fold it in.
- Assemble the casserole: Spread the creamy spinach mixture in the prepared dish. Nestle the seared chicken pieces into the sauce. Spoon a little sauce over the top so the chicken is coated.
- Top with cheese: Sprinkle remaining mozzarella and Parmesan over the casserole.
Add a pinch of red pepper flakes if you like a mild kick.
- Bake: Bake uncovered for 20–25 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the sauce is bubbling.
- Rest and garnish: Let the casserole rest 5–10 minutes to thicken slightly. Sprinkle with chopped parsley before serving.
Storage Instructions
- Refrigerator: Cool completely, then store in an airtight container for up to 4 days.
- Freezer: Freeze in freezer-safe containers for up to 2 months. Thaw overnight in the fridge.
- Reheat: Warm individual portions in the microwave at 50–70% power until hot, or bake covered at 325°F (165°C) until heated through.
Add a splash of cream if the sauce thickened too much.
Benefits of This Recipe
- Keto-friendly: Low in carbs, high in fat and protein, it fits cleanly into a ketogenic or low-carb plan.
- Nutrient-dense: Spinach adds fiber, iron, and vitamins A and K, while chicken brings lean protein.
- Meal-prep winner: Makes multiple servings that reheat well, saving time during the week.
- Family-approved flavors: Creamy, cheesy, and savory—without feeling heavy or greasy.
Pitfalls to Watch Out For
- Watery spinach: If using frozen spinach, squeeze out as much liquid as possible. Excess water can thin the sauce.
- Overcooked chicken: Sear lightly and finish cooking in the oven. Pull it out as soon as it hits 165°F to keep it tender.
- Grainy sauce: Add cream cheese to warm, not boiling liquid, and whisk until fully smooth before adding shredded cheese.
- Too salty: Use low-sodium broth and taste the sauce before adding extra salt, especially with Parmesan in the mix.
Variations You Can Try
- Sun-dried tomato and basil: Stir in chopped sun-dried tomatoes (packed in oil, drained) and fresh basil for a bright, Italian twist.
- Mushroom and thyme: Sauté sliced mushrooms with the onion and add a pinch of dried thyme.
- Buffalo-style: Add 2–3 tablespoons buffalo hot sauce to the cream sauce and top with a blend of mozzarella and blue cheese crumbles.
- Bacon lovers: Crisp 4–6 slices of bacon, crumble, and fold into the sauce.
Use the bacon fat to sauté the onions for extra flavor.
- Dairy adjustments: Swap part of the heavy cream for unsweetened almond milk and add an extra ounce of cream cheese to keep it thick.
- Cheese swap: Try Gruyère, provolone, or pepper jack for a different flavor profile.
FAQ
Can I use rotisserie chicken?
Yes. Shred or cube about 4 cups of cooked rotisserie chicken and fold it directly into the creamy spinach mixture. Skip the searing step and reduce bake time to 15–20 minutes, just until bubbly and hot.
Is this casserole gluten-free?
It is naturally gluten-free as written.
Always double-check your broth and seasonings to ensure there are no hidden gluten-containing additives.
Can I make it ahead?
You can assemble the casserole up to 24 hours in advance, cover, and refrigerate. When baking from cold, add 5–10 extra minutes to the bake time.
What can I serve with it?
Keep it keto with cauliflower rice, roasted broccoli, sautéed green beans, or a simple side salad with a lemony vinaigrette. If you’re not counting carbs, it pairs well with buttered noodles or crusty bread.
How do I prevent a greasy top?
Use a mix of cheeses that melt smoothly, like mozzarella and Parmesan, and avoid piling on too much oily cheese.
Let the casserole rest before serving so the sauce sets and doesn’t separate.
Can I use thighs instead of breasts?
Absolutely. Boneless, skinless thighs stay juicy and are very forgiving. Just check for doneness and adjust bake time as needed.
What if I don’t have cream cheese?
Use mascarpone or a combination of ricotta and shredded cheese.
If using ricotta, simmer the sauce a bit longer to thicken, and season generously.
In Conclusion
This Keto Creamy Spinach Chicken Casserole delivers all the comfort of a classic bake with smart, low-carb ingredients. It’s quick to prep, flexible with add-ins, and perfect for weeknights or meal prep. Keep the steps simple, watch your doneness, and you’ll have a creamy, cheesy dish that everyone at the table looks forward to.