Creamy Chicken Spinach Casserole

My youngest came home from college last weekend absolutely starving, and I threw this casserole together with whatever I had in the fridge. She took one bite and said this was the kind of dinner that makes you forget you ever ate dining hall food.

Last winter my neighbor dropped off some rotisserie chicken when I was recovering from surgery, and this casserole transformed that simple gift into something that felt like a proper Sunday dinner.

Ingredients

• 2 large chicken breasts, cooked and cubed: Rotisserie chicken works perfectly here and saves so much time
• 200 g fresh spinach: Fresh wilts down beautifully without the wateriness of frozen spinach
• 1 small yellow onion, finely chopped: Dice it small so it melts into the sauce
• 2 garlic cloves, minced: Fresh garlic makes all the difference in the creamy base
• 240 ml heavy cream or half-and-half: Heavy cream gives you that restaurant quality richness
• 120 g shredded mozzarella cheese: Reserve some for that golden top layer
• 60 g grated Parmesan cheese: Adds that salty umami depth
• 2 tbsp cream cheese: The secret to making the sauce velvety smooth
• 1 tbsp unsalted butter: Combined with olive oil for sautéing the aromatics
• 1 tbsp olive oil: Prevents the butter from burning over medium heat
• 1/2 tsp dried thyme: Earthy and pairs perfectly with cream and spinach
• 1/2 tsp ground black pepper: Fresh cracked pepper gives the best aroma
• 1/2 tsp salt: Adjust based on whether your chicken was preseasoned
• 1/2 cup breadcrumbs: Creates that irresistible crispy golden topping

Instructions

Preheat your oven:

Get it to 190°C and grease a baking dish while you prep

Sauté the aromatics:

Heat olive oil and butter in a skillet, cook onion 3-4 minutes until it turns translucent, then add garlic for just 1 minute

Wilt the spinach:

Toss in chopped spinach and cook 2-3 minutes until it collapses down

Build the sauce:

Lower heat, stir in cream, cream cheese, thyme, salt and pepper, cook 3 minutes until it thickens slightly

Combine everything:

Remove from heat, fold in chicken, half the mozzarella and half the Parmesan until evenly distributed

Assemble the casserole:

Transfer to your baking dish, top with remaining cheeses and breadcrumbs if using

Bake until golden:

Bake uncovered 20-25 minutes until the cheese bubbles and turns golden brown on top

Let it rest:

Wait 5 minutes before serving so the sauce sets up slightly

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My husband requested this for his birthday dinner instead of going out, which honestly says more than any restaurant review could.

Make It Your Own

Kale works beautifully instead of spinach if you prefer something more robust, just give it a couple extra minutes to wilt down in the pan.

Serving Suggestions

A crisp green salad with vinaigrette cuts through the richness, and crusty gluten free bread soaks up every last drop of that sauce.

Storage & Reheating

This keeps in the refrigerator for up to four days and actually tastes better the next day as the flavors meld together. Reheat at 160°C covered with foil so it does not dry out.

• Freeze individual portions for quick weeknight meals
• Let it cool completely before covering and refrigerating
• Add a splash of cream when reheating if the sauce seems thick

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There is something deeply satisfying about a casserole that brings everyone to the table without any fuss.

Recipe Questions & Answers

→ Can I use rotisserie chicken instead of raw chicken breasts?

Yes, rotisserie chicken is an excellent shortcut. Simply shred or cube about 500 grams of rotisserie chicken and fold it into the creamy mixture during assembly. This reduces your active prep time significantly since the chicken is already cooked.

→ Can I make this casserole ahead of time?

Absolutely. You can assemble the entire casserole up to 24 hours in advance, cover it tightly, and store it in the refrigerator. When ready to bake, add an extra 5 to 10 minutes to the baking time since the dish will be cold from the fridge.

→ What can I substitute for spinach?

Kale is the best substitute and works beautifully in this dish. You can also use Swiss chard or even frozen spinach that has been thawed and squeezed dry. Keep in mind that frozen spinach is more concentrated, so use about half the amount called for with fresh.

→ How do I store and reheat leftovers?

Store leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, cover with foil and warm in a 175°C (350°F) oven for about 15 minutes, or microwave individual portions for 1 to 2 minutes until heated through.

→ Can I freeze this casserole?

Yes, you can freeze it either before or after baking. For best results, assemble the casserole in a freezer-safe dish, wrap tightly with foil and plastic wrap, and freeze for up to 2 months. Thaw overnight in the refrigerator before baking as directed.

→ What side dishes pair well with this casserole?

A crisp green salad with a light vinaigrette balances the richness of the casserole beautifully. Roasted vegetables, steamed broccoli, or a side of cauliflower rice also complement it well while keeping the meal low in carbohydrates. A crusty bread or dinner rolls work great if carbs are not a concern.